user-1: Was the Buddha a bodhisattva before his awakening? Are there references from the suttas which point to when (possibly in past lives)?

Bodhisattva is the Sanskrit term for anyone who has generated
  Bodhicitta, a spontaneous wish and compassionate mind to attain
  Buddhahood for the benefit of all sentient beings.

The following appears to suggest that the four immeasurables may have been present in the Buddha's past lives:

The early Buddhist texts assert that pre-Buddha ancient Indian sages
  who taught these [four immeasurables] were earlier
  incarnations of the Buddha.

I apologize if the answer is obvious, but I haven't found a direct answer from the suttas. 

user254: The Jataka Tales (which is in the fifth Nikaya) say "Bodhisattva".
See also Buddha's past lives in the Pali Suttas outside of Jataka and Where is the description of the vow and the Bodhi tree?

user43: "Bodhisattva" is a reification, just like "a Buddha". To say that "Bodhisattva is a reification" - is, too, a reification. "For the benefit of all" is a reification. "For" and "benefit" and "all" - are reifications as well.

Śāriputra:  How then should the Bodhisattva, the great being, course
in perfect wisdom?
The Lord: Here the Bodhisattva, the great being, coursing in the
perfection of wisdom, truly a Bodhisattva, does not review a Bodhisattva, nor the word "Bodhisattva", nor the course of a Bodhisattva, (nor the perfection of wisdom, nor the word "perfection of wisdom". He does not review that "he courses", nor that "he does not course"). He does not review form, feeling, perception, formative forces, or consciousness. And why? Because the Bodhisattva, the great being, is actually empty of the own-being of a Bodhisattva, and because perfect wisdom is by its own-being empty. And why? That is its essential original nature. (For it is not through emptiness that form etc. is empty.) Nor is emptiness other than form, etc.
And why? The very form, etc., is emptiness, the very emptiness is
form, etc. And why? Because "Bodhisattva", "perfect wisdom", "form",
etc. are mere words. Because form, etc., are like an illusion. Illusions and
mere words do not stand at any point or spot; they are not, do not come
into being, are false to behold. For of what the own-being is seen to be an
illusion, of that there is no production or stopping, no defilement or
purification. Thus a Bodhisattva, a great being who courses in the perfection of wisdom, also does not review the production (of any dharma);
nor its stopping (or abiding, its decrease or increase), defilement or
purification. (He does not review form, etc., nor "enlightenment", nor
what is called an "enlightenment-being".) And why? Because words are
artificial. People have constructed a counter-dharma. They express it conventionally by means of an adventitious designation (which is
imagined and unreal, and they settle down in that conventional
expression). A Bodhisattva, a great being who courses in perfect wisdom,
does not review (that which is said to correspond to) all those words,
(does not get at them). Not reviewing them, (not getting at them, he does
not mind them), does not settle down in them.
Furthermore, a Bodhisattva, a great being who courses in the perfection
of wisdom, does not consider the fact that these are mere words, i.e.
this "Bodhisattva", this "enlightenment", this "Buddha", this
"perfection of wisdom", this "coursing in the perfection of wisdom",
this "form", etc. Just as one speaks of a "self, and yet no self is got at,
and no being, soul, personality, person, individual, or man, etc., on
account of unascertainable emptiness. And why? Because there a
Bodhisattva does also not review that by means of which he would settle
down. Coursing thus, a Bodhisattva, a great being courses in perfect
wisdom.

(from The Large Sutra on Perfect Wisdom, translated by E.Conze)

Additional detail on the bodhisattva Gautama’s reflection that motivated
him to set out on his quest can be gathered from another occurrence of
the ‘before awakening’ phrase, found in the Discourse on the Noble Quest,
the Ariyapariyesanā-sutta, and in its Madhyama-āgama parallel. The two
discourses contrast an average person’s quest for worldly things that are
subject to decay and death to the noble quest for what is not subject to decay
and death. Both reveal that this noble quest motivated the bodhisattva
to go forth in search of awakening, presenting his reflection in nearly identical terms:

“Being myself subject to old age … and death, now suppose I were to
search for what is free from old age … and death, for the unsurpassable
peace from bondage, Nirvāṇa.”
“Being myself truly subject to old age and death … suppose I were to
search … for what is free from old age and death … for the unsurpassable
peace from bondage, Nirvāṇa.”

This appears to be the only passage in the Pāli Nikāyas that explicitly formulates what motivated the bodhisattva Gautama to set out in search of
awakening. Notably, this formulation does not in any way reflect a concern
for others. Rather, according to this autobiographical report the bodhisattva
Gautama’s motivation was to find a solution for the problem of being “himself”,
attanā/自, subject to old age and death etc.
The same trait recurs in the description of the successful completion of
the bodhisattva’s quest, given in the Ariyapariyesanā-sutta and its parallel.
According to both versions, having arrived at the unsurpassable peace
from bondage that is free from old age and death, Gautama realized that he
had fully liberated himself from the prospect of future birth and existence.
Here, too, there is no reference at all to being able to save others. Instead,
the way the Buddha perceived his own awakening – according to early Buddhist discourse – is formulated entirely in terms of having freed himself.
The conspicuous lack of any concern for others becomes even more prominent
with the next episode recorded in the Ariyapariyesanā-sutta, according
to which the newly awakened Buddha was disinclined to teach others and decided to rather remain content with having reached liberation himself.
...
Such reluctance on the part of the newly awakened Buddha is not easily
reconciled with the notion common to all Buddhist traditions that he had
prepared himself over immense periods of time with the sole intention of
executing the task of leading others to liberation. Judging from the account
given in the Ariyapariyesanā-sutta, the reason for the Buddha’s disinclination
to teach was that it would be fatiguing (klamatha) and vexing (viheṭhā)
for him if others should fail to understand the profound truth he had
realized. Similar reasons recur in other reports of his initial hesitation to
teach, found in an Ekottarika-āgama discourse, in the Catuṣpariṣat-sūtra, and in the Vinayas of the Dharmaguptaka, Lokottaravāda-Mahāsāṃghika,
Mahīśāsaka and (Mūla-)Sarvāstivāda traditions.
That is, when reflecting on the possibility of sharing his discovery with
others, according to a range of sources the Buddha considered the matter
entirely from the perspective of how it would affect himself. This ties in
with the observations made above regarding his motivation and his reaching
of the final goal. Throughout, according to these texts the Buddha’s predominant
concern is with himself, when he forms his initial motivation to
set out for awakening, when he successfully completes his quest, and even
when he reflects about what course of action is to be taken next.
This certainly does not imply that from the perspective of the early discourses
the Buddha was not compassionate. [...] However, the early
discourses do not give any indication that a concern for others was part of
the motivation of the bodhisattva Gautama to set out on his quest for awakening,
nor does the successful reaching of this goal show any immediate
relationship to teaching activity.
...
In sum, in early Buddhist thought the compassionate impulse to become
active for the sake of others was associated with the Buddha as well as with
arhats and those who aspire to become arhats, but was not seen as a quality
that motivated the bodhisattva’s quest for awakening.

(from The Genesis of the Bodhisattva Ideal, by Analayo Bhikkhu)

user13375: Absolutely he was! In fact, there is no way to become a Buddha without becoming a Bodhisattva first. Numerous Mahayana Sutras attest to this. Without developing the immeasurable compassion of a Bodhisattva there is no way for a sentient being to become a Buddha.
As for the Theravada who do not regard the Mahayana Sutras as authentic Buddhavacana: the Pali canon still has many references to the past lives of the Buddha where he was a Bodhisattva. And they are not all part of the so-called Jataka tales either. See here for many examples.
You can find an example here - AN 5.196 - which is not one of the Jataka tales:

“When the Tathagata—worthy & rightly self-awakened—was still just an
  unawakened bodhisatta, five great dreams appeared to him. Which five?
“When the Tathagata—worthy & rightly self-awakened—was still just an
  unawakened bodhisatta, this great earth was his great bed. The
  Himalayas, king of mountains, was his pillow. His left hand rested in
  the eastern sea, his right hand in the western sea, and both feet in
  the southern sea. When the Tathagata—worthy & rightly
  self-awakened—was still just an unawakened bodhisatta, this was the
  first great dream that appeared to him.

Emphasis mine.
And here is the original Pali:

“Tathāgatassa, bhikkhave, arahato sammāsambuddhassa pubbeva sambodhā
  anabhisambuddhassa bodhisattasseva sato pañca mahāsupinā pāturahesuṃ.
  Katame pañca? Tathāgatassa, bhikkhave, arahato sammāsambuddhassa
  pubbeva sambodhā anabhisambuddhassa bodhisattasseva sato ayaṃ
  mahāpathavī mahāsayanaṃ ahosi, himavā pabbatarājā bibbohanaṃ ahosi,
  puratthime samudde vāmo hattho ohito ahosi, pacchime samudde dakkhiṇo
  hattho ohito ahosi, dakkhiṇe samudde ubho pādā ohitā ahesuṃ.
  Tathāgatassa, bhikkhave, arahato sammāsambuddhassa pubbeva sambodhā
  anabhisambuddhassa bodhisattasseva sato ayaṃ paṭhamo mahāsupino
  pāturahosi.

Emphasis mine again.
Here is another example from the Pali-canon which is not one of the Jataka tales:

“So it is, Ananda. So it is. Even I myself, before my Awakening, when
  I was still an unawakened Bodhisatta, thought: ‘Renunciation is good.
  Seclusion is good.’ But my heart didn’t leap up at renunciation,
  didn’t grow confident, steadfast, or firm, seeing it as peace. The
  thought occurred to me: ‘What is the cause, what is the reason, why my
  heart doesn’t leap up at renunciation, doesn’t grow confident,
  steadfast, or firm, seeing it as peace?’

Emphasis mine.
And here is the original Pali:

“Evametaṃ, ānanda, evametaṃ, ānanda. Mayhampi kho, ānanda, pubbeva
  sambodhā anabhisambuddhassa bodhisattasseva sato etadahosi: ‘sādhu
  nekkhammaṃ, sādhu paviveko’ti. Tassa mayhaṃ, ānanda, nekkhamme cittaṃ
  na pakkhandati nappasīdati na santiṭṭhati na vimuccati etaṃ santanti
  passato. Tassa mayhaṃ, ānanda, etadahosi: ‘ko nu kho hetu ko paccayo,
  yena me nekkhamme cittaṃ na pakkhandati nappasīdati na santiṭṭhati na
  vimuccati etaṃ santanti passato’?

And here is yet another one:

“Bhikkhus, before my enlightenment, while I was still a bodhisatta,
  not yet fully enlightened, it occurred to me: “What now is feeling?
  What is the origin of feeling? What is the way leading to the
  origination of feeling? What is the cessation of feeling? What is the
  way leading to the cessation of feeling? What is the gratification in
  feeling? What is the danger? What is the escape?”

Here is another one:

‘Both the quotations you have made, O king, are accurate. But when he
  spoke of Āḷāra Kālāma as his teacher, that was a statement made with
  reference to the fact of his having been his teacher while he (Gotama)
  was still a Bodisat and before he had attained to insight and to
  Buddhahood; and there were five such teachers, O king, under whose
  tuition the Bodisat spent his time in various places—his teachers when
  he was still a Bodisat, before he had attained to insight and to
  Buddhahood. And who were these five?

And another:

At Sāvatthī. “Mendicants, before my awakening—when I was still
  unawakened but intent on awakening—I thought: ‘What’s the path and
  practice for developing the bases of psychic power?’

Now, why did I emphasize "intent on awakening?" Because, this translation chose to use "intent on awakening" as a substitute for the original Pali which has this: 

Sāvatthinidānaṃ. “Pubbeva me, bhikkhave, sambodhā anabhisambuddhassa
  bodhisattasseva sato etadahosi: ‘ko nu kho maggo, kā paṭipadā
  iddhipādabhāvanāyā’ti?

So I hope you can clearly see that according to both the Mahayana and the Theravada that the Buddha was an unenlightened Bodhisattva before he became the Buddha.
Now, was the Buddha as a Bodhisattva for the benefit of all? Here is a passage from a canonical Pali sutta describing the Bodhisattva Gotama being born into the world for the benefit of all:

“The Bodhisatta, the foremost jewel, unequaled, has been born for
  welfare & happiness in the human world, in a town in the Sakyan
  countryside, Lumbini. That’s why we’re contented, so wildly elated.
  He, the highest of all beings, the ultimate person, a bull among men,
  highest of all people, will set turning the Wheel [of Dhamma] in the
  forest named after the seers, like a strong, roaring lion, the
  conqueror of beasts.”

And from that same sutta here is the testament to his motivation:

He, seeing the utmost purity, will set rolling the Wheel of Dhamma
  through sympathy for the welfare of many.

So, to sum up: have no doubt The Buddha was a Bodhisattva who manifested the Mind of Enlightenment - pure Bodhicitta - for the benefit of all before his awakening.

-1: <p>Was the Buddha a bodhisattva before his awakening? Are there references from the suttas which point to when (possibly in past lives)?</p>

<blockquote>
  <p><a href="https://en.wikipedia.org/wiki/Bodhisattva" rel="nofollow noreferrer">Bodhisattva</a> is the Sanskrit term for anyone who has generated
  Bodhicitta, a spontaneous wish and compassionate mind to attain
  Buddhahood for the benefit of all sentient beings.</p>
</blockquote>

<p>The following appears to suggest that the <em>four immeasurables</em> may have been present in the Buddha's past lives:</p>

<blockquote>
  <p>The early Buddhist texts assert that pre-Buddha ancient Indian sages
  who taught these [<a href="https://en.wikipedia.org/wiki/Brahmavihara#Origins" rel="nofollow noreferrer">four immeasurables</a>] were earlier
  incarnations of the Buddha.</p>
</blockquote>

<p>I apologize if the answer is obvious, but I haven't found a direct answer from the suttas. </p>
 254: <p>The <a href="https://en.wikipedia.org/wiki/Jataka_tales" rel="nofollow noreferrer">Jataka Tales</a> (which is in the fifth Nikaya) say "Bodhisattva".</p>

<p>See also <a href="https://buddhism.stackexchange.com/q/26521/254">Buddha&#39;s past lives in the Pali Suttas outside of Jataka</a> and <a href="https://buddhism.stackexchange.com/q/14362/254">Where is the description of the vow and the Bodhi tree?</a></p>
 43: <p>&quot;Bodhisattva&quot; is a reification, just like &quot;a Buddha&quot;. To say that &quot;Bodhisattva is a reification&quot; - is, too, a reification. &quot;For the benefit of all&quot; is a reification. &quot;For&quot; and &quot;benefit&quot; and &quot;all&quot; - are reifications as well.</p>
<blockquote>
<p>Śāriputra:  How then should the Bodhisattva, the great being, course
in perfect wisdom?</p>
<p>The Lord: Here the Bodhisattva, the great being, coursing in the
perfection of wisdom, truly a Bodhisattva, does not review a Bodhisattva, nor the word &quot;Bodhisattva&quot;, nor the course of a Bodhisattva, (nor the perfection of wisdom, nor the word &quot;perfection of wisdom&quot;. He does not review that &quot;he courses&quot;, nor that &quot;he does not course&quot;). He does not review form, feeling, perception, formative forces, or consciousness. And why? Because the Bodhisattva, the great being, is actually empty of the own-being of a Bodhisattva, and because perfect wisdom is by its own-being empty. And why? That is its essential original nature. (For it is not through emptiness that form etc. is empty.) Nor is emptiness other than form, etc.</p>
<p>And why? The very form, etc., is emptiness, the very emptiness is
form, etc. And why? Because &quot;Bodhisattva&quot;, &quot;perfect wisdom&quot;, &quot;form&quot;,
etc. are mere words. Because form, etc., are like an illusion. Illusions and
mere words do not stand at any point or spot; they are not, do not come
into being, are false to behold. For of what the own-being is seen to be an
illusion, of that there is no production or stopping, no defilement or
purification. Thus a Bodhisattva, a great being who courses in the perfection of wisdom, also does not review the production (of any dharma);
nor its stopping (or abiding, its decrease or increase), defilement or
purification. (He does not review form, etc., nor &quot;enlightenment&quot;, nor
what is called an &quot;enlightenment-being&quot;.) And why? Because words are
artificial. People have constructed a counter-dharma. They express it conventionally by means of an adventitious designation (which is
imagined and unreal, and they settle down in that conventional
expression). A Bodhisattva, a great being who courses in perfect wisdom,
does not review (that which is said to correspond to) all those words,
(does not get at them). Not reviewing them, (not getting at them, he does
not mind them), does not settle down in them.</p>
<p>Furthermore, a Bodhisattva, a great being who courses in the perfection
of wisdom, does not consider the fact that these are mere words, i.e.
this &quot;Bodhisattva&quot;, this &quot;enlightenment&quot;, this &quot;Buddha&quot;, this
&quot;perfection of wisdom&quot;, this &quot;coursing in the perfection of wisdom&quot;,
this &quot;form&quot;, etc. Just as one speaks of a &quot;self, and yet no self is got at,
and no being, soul, personality, person, individual, or man, etc., on
account of unascertainable emptiness. And why? Because there a
Bodhisattva does also not review that by means of which he would settle
down. Coursing thus, a Bodhisattva, a great being courses in perfect
wisdom.</p>
</blockquote>
<p>(from The Large Sutra on Perfect Wisdom, translated by E.Conze)</p>
<blockquote>
<p>Additional detail on the bodhisattva Gautama’s reflection that motivated
him to set out on his quest can be gathered from another occurrence of
the ‘before awakening’ phrase, found in the Discourse on the Noble Quest,
the <em>Ariyapariyesanā-sutta</em>, and in its <em>Madhyama-āgama</em> parallel. The two
discourses contrast an average person’s quest for worldly things that are
subject to decay and death to the noble quest for what is not subject to decay
and death. Both reveal that this noble quest motivated the bodhisattva
to go forth in search of awakening, presenting his reflection in nearly identical terms:</p>
<blockquote>
<p>“Being myself subject to old age … and death, now suppose I were to
search for what is free from old age … and death, for the unsurpassable
peace from bondage, Nirvāṇa.”<br />
“Being myself truly subject to old age and death … suppose I were to
search … for what is free from old age and death … for the unsurpassable
peace from bondage, Nirvāṇa.”</p>
</blockquote>
<p>This appears to be the only passage in the Pāli Nikāyas that explicitly formulates what motivated the bodhisattva Gautama to set out in search of
awakening. Notably, this formulation does not in any way reflect a concern
for others. Rather, according to this autobiographical report the bodhisattva
Gautama’s motivation was to find a solution for the problem of being “himself”,
attanā/自, subject to old age and death etc.</p>
<p>The same trait recurs in the description of the successful completion of
the bodhisattva’s quest, given in the <em>Ariyapariyesanā-sutta</em> and its parallel.
According to both versions, having arrived at the unsurpassable peace
from bondage that is free from old age and death, Gautama realized that he
had fully liberated himself from the prospect of future birth and existence.
Here, too, there is no reference at all to being able to save others. Instead,
the way the Buddha perceived his own awakening – according to early Buddhist discourse – is formulated entirely in terms of having freed himself.</p>
<p>The conspicuous lack of any concern for others becomes even more prominent
with the next episode recorded in the <em>Ariyapariyesanā-sutta</em>, according
to which the newly awakened Buddha was disinclined to teach others and decided to rather remain content with having reached liberation himself.</p>
<p>...</p>
<p>Such reluctance on the part of the newly awakened Buddha is not easily
reconciled with the notion common to all Buddhist traditions that he had
prepared himself over immense periods of time with the sole intention of
executing the task of leading others to liberation. Judging from the account
given in the Ariyapariyesanā-sutta, the reason for the Buddha’s disinclination
to teach was that it would be fatiguing (<em>klamatha</em>) and vexing (<em>viheṭhā</em>)
for him if others should fail to understand the profound truth he had
realized. Similar reasons recur in other reports of his initial hesitation to
teach, found in an <em>Ekottarika-āgama</em> discourse, in the <em>Catuṣpariṣat-sūtra</em>, and in the <em>Vinayas</em> of the Dharmaguptaka, Lokottaravāda-Mahāsāṃghika,
Mahīśāsaka and (Mūla-)Sarvāstivāda traditions.</p>
<p>That is, when reflecting on the possibility of sharing his discovery with
others, according to a range of sources the Buddha considered the matter
entirely from the perspective of how it would affect himself. This ties in
with the observations made above regarding his motivation and his reaching
of the final goal. Throughout, according to these texts the Buddha’s predominant
concern is with himself, when he forms his initial motivation to
set out for awakening, when he successfully completes his quest, and even
when he reflects about what course of action is to be taken next.</p>
<p>This certainly does not imply that from the perspective of the early discourses
the Buddha was not compassionate. [...] However, the early
discourses do not give any indication that a concern for others was part of
the motivation of the bodhisattva Gautama to set out on his quest for awakening,
nor does the successful reaching of this goal show any immediate
relationship to teaching activity.</p>
<p>...</p>
<p>In sum, in early Buddhist thought the compassionate impulse to become
active for the sake of others was associated with the Buddha as well as with
arhats and those who aspire to become arhats, but was not seen as a quality
that motivated the bodhisattva’s quest for awakening.</p>
</blockquote>
<p>(from <a href="https://www.buddhismuskunde.uni-hamburg.de/pdf/5-personen/analayo/genesis-bodhisattva.pdf" rel="nofollow noreferrer">The Genesis of the Bodhisattva Ideal</a>, by Analayo Bhikkhu)</p>
 13375: <p>Absolutely he was! In fact, there is no way to become a Buddha without becoming a Bodhisattva first. Numerous Mahayana Sutras attest to this. Without developing the immeasurable compassion of a Bodhisattva there is no way for a sentient being to become a Buddha.</p>

<p>As for the Theravada who do not regard the Mahayana Sutras as authentic Buddhavacana: the Pali canon still has <a href="https://suttacentral.net/search?query=Bodhisatta" rel="nofollow noreferrer">many references to the past lives</a> of the Buddha where he was a Bodhisattva. And they are not all part of the so-called Jataka tales either. See <a href="https://suttacentral.net/search?query=bodhisattasseva" rel="nofollow noreferrer">here</a> for many examples.</p>

<p>You can find an example <a href="https://suttacentral.net/an5.196/en/thanissaro" rel="nofollow noreferrer">here</a> - AN 5.196 - which is not one of the Jataka tales:</p>

<blockquote>
  <p>“When the Tathagata—worthy &amp; rightly self-awakened—was still just an
  <strong>unawakened bodhisatta</strong>, five great dreams appeared to him. Which five?</p>
  
  <p>“When the Tathagata—worthy &amp; rightly self-awakened—was still just an
  <strong>unawakened bodhisatta</strong>, this great earth was his great bed. The
  Himalayas, king of mountains, was his pillow. His left hand rested in
  the eastern sea, his right hand in the western sea, and both feet in
  the southern sea. When the Tathagata—worthy &amp; rightly
  self-awakened—was still just an <strong>unawakened bodhisatta</strong>, this was the
  first great dream that appeared to him.</p>
</blockquote>

<p>Emphasis mine.</p>

<p>And here is the original Pali:</p>

<blockquote>
  <p>“Tathāgatassa, bhikkhave, arahato sammāsambuddhassa pubbeva sambodhā
  anabhisambuddhassa <strong>bodhisattasseva</strong> sato pañca mahāsupinā pāturahesuṃ.
  Katame pañca? Tathāgatassa, bhikkhave, arahato sammāsambuddhassa
  pubbeva sambodhā anabhisambuddhassa <strong>bodhisattasseva</strong> sato ayaṃ
  mahāpathavī mahāsayanaṃ ahosi, himavā pabbatarājā bibbohanaṃ ahosi,
  puratthime samudde vāmo hattho ohito ahosi, pacchime samudde dakkhiṇo
  hattho ohito ahosi, dakkhiṇe samudde ubho pādā ohitā ahesuṃ.
  Tathāgatassa, bhikkhave, arahato sammāsambuddhassa pubbeva sambodhā
  anabhisambuddhassa <strong>bodhisattasseva</strong> sato ayaṃ paṭhamo mahāsupino
  pāturahosi.</p>
</blockquote>

<p>Emphasis mine again.</p>

<p>Here is <a href="https://suttacentral.net/an9.41/en/thanissaro" rel="nofollow noreferrer">another example</a> from the Pali-canon which is not one of the Jataka tales:</p>

<blockquote>
  <p>“So it is, Ananda. So it is. Even I myself, before my Awakening, when
  I was still an <strong>unawakened Bodhisatta</strong>, thought: ‘Renunciation is good.
  Seclusion is good.’ But my heart didn’t leap up at renunciation,
  didn’t grow confident, steadfast, or firm, seeing it as peace. The
  thought occurred to me: ‘What is the cause, what is the reason, why my
  heart doesn’t leap up at renunciation, doesn’t grow confident,
  steadfast, or firm, seeing it as peace?’</p>
</blockquote>

<p>Emphasis mine.</p>

<p>And here is the original Pali:</p>

<blockquote>
  <p>“Evametaṃ, ānanda, evametaṃ, ānanda. Mayhampi kho, ānanda, pubbeva
  sambodhā anabhisambuddhassa <strong>bodhisattasseva</strong> sato etadahosi: ‘sādhu
  nekkhammaṃ, sādhu paviveko’ti. Tassa mayhaṃ, ānanda, nekkhamme cittaṃ
  na pakkhandati nappasīdati na santiṭṭhati na vimuccati etaṃ santanti
  passato. Tassa mayhaṃ, ānanda, etadahosi: ‘ko nu kho hetu ko paccayo,
  yena me nekkhamme cittaṃ na pakkhandati nappasīdati na santiṭṭhati na
  vimuccati etaṃ santanti passato’?</p>
</blockquote>

<p>And here is <a href="https://suttacentral.net/sn36.24/en/bodhi" rel="nofollow noreferrer">yet another one:</a></p>

<blockquote>
  <p>“Bhikkhus, before my enlightenment, <strong>while I was still a bodhisatta</strong>,
  not yet fully enlightened, it occurred to me: “What now is feeling?
  What is the origin of feeling? What is the way leading to the
  origination of feeling? What is the cessation of feeling? What is the
  way leading to the cessation of feeling? What is the gratification in
  feeling? What is the danger? What is the escape?”</p>
</blockquote>

<p>Here is <a href="https://suttacentral.net/mil5.5.11/en/tw_rhysdavids" rel="nofollow noreferrer">another one:</a></p>

<blockquote>
  <p>‘Both the quotations you have made, O king, are accurate. But when he
  spoke of Āḷāra Kālāma as his teacher, that was a statement made with
  reference to the fact of his having been his teacher while he (Gotama)
  was still a <strong>Bodisat</strong> and before he had attained to insight and to
  Buddhahood; and there were five such teachers, O king, under whose
  tuition the <strong>Bodisat</strong> spent his time in various places—his teachers when
  he was still a <strong>Bodisat</strong>, before he had attained to insight and to
  Buddhahood. And who were these five?</p>
</blockquote>

<p>And <a href="https://suttacentral.net/sn51.21/en/sujato" rel="nofollow noreferrer">another:</a></p>

<blockquote>
  <p>At Sāvatthī. “Mendicants, before my awakening—when I was still
  unawakened but <strong>intent on awakening</strong>—I thought: ‘What’s the path and
  practice for developing the bases of psychic power?’</p>
</blockquote>

<p>Now, why did I emphasize "intent on awakening?" Because, this translation chose to use "intent on awakening" as a substitute for the original Pali which has <a href="https://suttacentral.net/sn51.21/pli/ms" rel="nofollow noreferrer">this:</a> </p>

<blockquote>
  <p>Sāvatthinidānaṃ. “Pubbeva me, bhikkhave, sambodhā anabhisambuddhassa
  <strong>bodhisattasseva</strong> sato etadahosi: ‘ko nu kho maggo, kā paṭipadā
  iddhipādabhāvanāyā’ti?</p>
</blockquote>

<p>So I hope you can clearly see that according to both the Mahayana and the Theravada that the Buddha was an unenlightened Bodhisattva before he became the Buddha.</p>

<p>Now, was the Buddha as a Bodhisattva for the benefit of all? Here is a <a href="https://www.dhammatalks.org/suttas/KN/StNp/StNp3_11.html" rel="nofollow noreferrer">passage from a canonical Pali sutta</a> describing the Bodhisattva Gotama being born into the world for the benefit of all:</p>

<blockquote>
  <p>“The <strong>Bodhisatta</strong>, the foremost jewel, unequaled, <strong>has been born for
  welfare &amp; happiness in the human world</strong>, in a town in the Sakyan
  countryside, Lumbini. That’s why we’re contented, so wildly elated.
  He, the highest of all beings, the ultimate person, a bull among men,
  highest of all people, will set turning the Wheel [of Dhamma] in the
  forest named after the seers, like a strong, roaring lion, the
  conqueror of beasts.”</p>
</blockquote>

<p>And from that same sutta here is the testament to his motivation:</p>

<blockquote>
  <p><strong>He, seeing the utmost purity, will set rolling the Wheel of Dhamma
  through sympathy for the welfare of many.</strong></p>
</blockquote>

<p>So, to sum up: have no doubt The Buddha was a Bodhisattva who manifested the Mind of Enlightenment - pure Bodhicitta - for the benefit of all before his awakening.</p>
