user21235: I wanted to know if someone could reference passages from the canon where the Buddha teaches about mindfulness. If such passages exist that is.
I was wondering about it because terms and explanations surrounding mindfulness can sound very modern and almost technical at times, depending on who explains it. Has mindfulness, as practiced in this modern age, any roots in the original teachings of the Buddha (as taught by Himself), or did this arise in more recent times?
E.g. Vietnamese Monk Thich Nanh Hanh's school of mindfulness is an entire sect devoted to the practice of mindfulness.
But is there any canonical, textual evidence? I couldn't find anything.
Thanks.

user-1: 
Abhidhamma


Therein what is mindfulness-awakening-factor? Herein a monk is
mindful, furnished with excellent mindfulness-penetration, he
remembers, remembers constantly, what has long been done and long been
said (concerning release). This is called
mindfulness-awakening-factor. (1)
That which is mindfulness, recollection, recall, mindfulness,
remembrance, bearing (in mind), not losing, not confusing,
mindfulness, the Faculty of Mindfulness, the Strength of Mindfulness,
Right Mindfulness: this is called ‘mindfulness.’
The mindfulness which on that occasion is recollecting, calling back
to mind; the mindfulness which is remembering, bearing in mind, the
opposite of superficiality and of obliviousness; mindfulness as
faculty, mindfulness as power, right mindfulness—this is the faculty
of mindfulness that there then is.


Sutta


Suppose, monk, that there were a royal frontier fortress with strong
walls & ramparts and six gates. In it would be a wise, experienced,
intelligent gatekeeper to keep out those he didn't know and to let in
those he did. A swift pair of messengers, coming from the east, would
say to the gatekeeper, 'Where, my good man, is the commander of this
fortress?' He would say, 'There he is, sirs, sitting in the central
square.' The swift pair of messengers, delivering their accurate
report to the commander of the fortress, would then go back by the
route by which they had come. Then a swift pair of messengers, coming
from the west... the north... the south, would say to the gatekeeper,
'Where, my good man, is the commander of this fortress?' He would say,
'There he is, sirs, sitting in the central square.' The swift pair of
messengers, delivering their accurate report to the commander of the
fortress, would then go back by the route by which they had come.
"I have given you this simile, monk, to convey a message. The message
is this: The fortress stands for this body — composed of four
elements, born of mother & father, nourished with rice & barley gruel,
subject to constant rubbing & abrasion, to breaking & falling apart.
The six gates stand for the six internal sense media. The gatekeeper
stands for mindfulness. The swift pair of messengers stands for
tranquillity (samatha) and insight (vipassana). The commander of the
fortress stands for consciousness. The central square stands for the
four great elements: the earth-property, the liquid-property, the
fire-property, & the wind-property. The accurate report stands for
Unbinding (nibbana). The route by which they had come stands for the
noble eightfold path: right view, right resolve, right speech, right
action, right livelihood, right effort, right mindfulness, right
concentration."


user471: Here is a good description of mindfulness (sati) directed to the body. It's similar for mindfulness directed to other things.

“Bhikkhus, suppose that on hearing, ‘The most beautiful girl of the
land! The most beautiful girl of the land!’ a great crowd of people
would assemble. Now that most beautiful girl of the land would dance
exquisitely and sing exquisitely. On hearing, ‘The most beautiful girl
of the land is dancing! The most beautiful girl of the land is
singing!’ an even larger crowd of people would assemble. Then a man
would come along, wishing to live, not wishing to die, wishing for
happiness, averse to suffering. Someone would say to him: ‘Good man,
you must carry around this bowl of oil filled to the brim between the
crowd and the most beautiful girl of the land. A man with a drawn
sword will be following right behind you, and wherever you spill even
a little of it, right there he will fell your head.’
“What do you think, bhikkhus, would that man stop attending to that
bowl of oil and out of negligence turn his attention outwards?”
“No, venerable sir.”
“I have made up this simile, bhikkhus, in order to convey a meaning.
This here is the meaning: ‘The bowl of oil filled to the brim’: this
is a designation for mindfulness directed to the body. Therefore,
bhikkhus, you should train yourselves thus: ‘We will develop and
cultivate mindfulness directed to the body, make it our vehicle, make
it our basis, stabilize it, exercise ourselves in it, and fully
perfect it.’ Thus, bhikkhus, should you train yourselves.”
SN 47.20


user16297: There are 56 samyutta's in the SN, the 47'th SN is devoted to the topic of "mindfulness" (sati).
SN 47 Sati-'paṭṭhāna  Saṃyutta
https://lucid24.org/sn/sn47/index.html (disclosure: my website, my translations are derived from B. Sujato)
The first 10 suttas especially are particularly important on the subject. But even reading various English translations of those 10 suttas, you can get quite a different idea of what the practice of sati means. With a bad translation it's easy to arrive at wrong interpretations of 'sati' that totally miss the mark.
So SN 47 should be your first stop for authoritative passages, other suttas are mentioned here, along with brief explanations:
https://lucid24.org/sted/8aam/7sati/index.html
A great way to check if your understanding of 'sati' is correct, is with the fortress sutta simile, of AN 7.67.
https://lucid24.org/an/an07/an07-0067/index.html
If it's a correct sati, then the wise general who guards the gate is going to be effective. If it's a wrong understanding of sati, like many modern "mindfulness" teachers teach, then the guard is going to let bad guys waltz right into the fortress.

21235: <p>I wanted to know if someone could reference passages from the canon where the Buddha teaches about mindfulness. If such passages exist that is.</p>
<p>I was wondering about it because terms and explanations surrounding mindfulness can sound very modern and almost technical at times, depending on who explains it. Has mindfulness, as practiced in this modern age, any roots in the original teachings of the Buddha (as taught by Himself), or did this arise in more recent times?
E.g. Vietnamese Monk Thich Nanh Hanh's school of mindfulness is an entire sect devoted to the practice of mindfulness.
But is there any canonical, textual evidence? I couldn't find anything.</p>
<p>Thanks.</p>
 -1: <ul>
<li>Abhidhamma</li>
</ul>
<blockquote>
<p>Therein what is mindfulness-awakening-factor? Herein a monk is
mindful, furnished with excellent mindfulness-penetration, he
remembers, remembers constantly, what has long been done and long been
said (concerning release). This is called
mindfulness-awakening-factor. (1)</p>
<p>That which is mindfulness, recollection, recall, mindfulness,
remembrance, bearing (in mind), not losing, not confusing,
mindfulness, the Faculty of Mindfulness, the Strength of Mindfulness,
Right Mindfulness: this is called ‘mindfulness.’</p>
<p>The mindfulness which on that occasion is recollecting, calling back
to mind; the mindfulness which is remembering, bearing in mind, the
opposite of superficiality and of obliviousness; mindfulness as
faculty, mindfulness as power, right mindfulness—this is the faculty
of mindfulness that there then is.</p>
</blockquote>
<ul>
<li>Sutta</li>
</ul>
<blockquote>
<p>Suppose, monk, that there were a royal frontier fortress with strong
walls &amp; ramparts and six gates. In it would be a wise, experienced,
intelligent gatekeeper to keep out those he didn't know and to let in
those he did. A swift pair of messengers, coming from the east, would
say to the gatekeeper, 'Where, my good man, is the commander of this
fortress?' He would say, 'There he is, sirs, sitting in the central
square.' The swift pair of messengers, delivering their accurate
report to the commander of the fortress, would then go back by the
route by which they had come. Then a swift pair of messengers, coming
from the west... the north... the south, would say to the gatekeeper,
'Where, my good man, is the commander of this fortress?' He would say,
'There he is, sirs, sitting in the central square.' The swift pair of
messengers, delivering their accurate report to the commander of the
fortress, would then go back by the route by which they had come.</p>
<p>&quot;I have given you this simile, monk, to convey a message. The message
is this: The fortress stands for this body — composed of four
elements, born of mother &amp; father, nourished with rice &amp; barley gruel,
subject to constant rubbing &amp; abrasion, to breaking &amp; falling apart.
The six gates stand for the six internal sense media. The gatekeeper
stands for mindfulness. The swift pair of messengers stands for
tranquillity (samatha) and insight (vipassana). The commander of the
fortress stands for consciousness. The central square stands for the
four great elements: the earth-property, the liquid-property, the
fire-property, &amp; the wind-property. The accurate report stands for
Unbinding (nibbana). The route by which they had come stands for the
noble eightfold path: right view, right resolve, right speech, right
action, right livelihood, right effort, right mindfulness, right
concentration.&quot;</p>
</blockquote>
 471: <p>Here is a good description of mindfulness (<em>sati</em>) directed to the body. It's similar for mindfulness directed to other things.</p>
<blockquote>
<p>“Bhikkhus, suppose that on hearing, ‘The most beautiful girl of the
land! The most beautiful girl of the land!’ a great crowd of people
would assemble. Now that most beautiful girl of the land would dance
exquisitely and sing exquisitely. On hearing, ‘The most beautiful girl
of the land is dancing! The most beautiful girl of the land is
singing!’ an even larger crowd of people would assemble. Then a man
would come along, wishing to live, not wishing to die, wishing for
happiness, averse to suffering. Someone would say to him: ‘Good man,
you must carry around this bowl of oil filled to the brim between the
crowd and the most beautiful girl of the land. A man with a drawn
sword will be following right behind you, and wherever you spill even
a little of it, right there he will fell your head.’</p>
<p>“What do you think, bhikkhus, would that man stop attending to that
bowl of oil and out of negligence turn his attention outwards?”</p>
<p>“No, venerable sir.”</p>
<p>“I have made up this simile, bhikkhus, in order to convey a meaning.
This here is the meaning: ‘The bowl of oil filled to the brim’: this
is a designation for mindfulness directed to the body. Therefore,
bhikkhus, you should train yourselves thus: ‘We will develop and
cultivate mindfulness directed to the body, make it our vehicle, make
it our basis, stabilize it, exercise ourselves in it, and fully
perfect it.’ Thus, bhikkhus, should you train yourselves.”<br />
<a href="https://suttacentral.net/sn47.20/en/bodhi" rel="nofollow noreferrer">SN 47.20</a></p>
</blockquote>
 16297: <p>There are 56 samyutta's in the SN, the 47'th SN is devoted to the topic of &quot;mindfulness&quot; (sati).</p>
<p>SN 47 Sati-'paṭṭhāna  Saṃyutta
<a href="https://lucid24.org/sn/sn47/index.html" rel="nofollow noreferrer">https://lucid24.org/sn/sn47/index.html</a> (disclosure: my website, my translations are derived from B. Sujato)</p>
<p>The first 10 suttas especially are particularly important on the subject. But even reading various English translations of those 10 suttas, you can get quite a different idea of what the practice of sati means. With a bad translation it's easy to arrive at wrong interpretations of 'sati' that totally miss the mark.</p>
<p>So SN 47 should be your first stop for authoritative passages, other suttas are mentioned here, along with brief explanations:
<a href="https://lucid24.org/sted/8aam/7sati/index.html" rel="nofollow noreferrer">https://lucid24.org/sted/8aam/7sati/index.html</a></p>
<p>A great way to check if your understanding of 'sati' is correct, is with the fortress sutta simile, of AN 7.67.
<a href="https://lucid24.org/an/an07/an07-0067/index.html" rel="nofollow noreferrer">https://lucid24.org/an/an07/an07-0067/index.html</a></p>
<p>If it's a correct sati, then the wise general who guards the gate is going to be effective. If it's a wrong understanding of sati, like many modern &quot;mindfulness&quot; teachers teach, then the guard is going to let bad guys waltz right into the fortress.</p>
