user10844: I've seen statements like "When one is in jhana, all defilements are suppressed temporarily." Is there any scriptural source for this?

user471: The closest that I can find so far, from the Piti Sutta (AN 5.176):

[The Blessed One said:] "Excellent, Sariputta. Excellent. When a
  disciple of the noble ones enters & remains in seclusion & rapture,
  there are five possibilities that do not exist at that time: The pain
  & distress dependent on sensuality do not exist at that time. The
  pleasure & joy dependent on sensuality do not exist at that time. The
  pain & distress dependent on what is unskillful do not exist at that
  time. The pleasure & joy dependent on what is unskillful do not exist
  at that time. The pain & distress dependent on what is skillful do not
  exist at that time. When a disciple of the noble ones enters & remains
  in seclusion & rapture, these five possibilities do not exist at that
  time."

This means that only the pleasure and joy dependent on what is skillful can exist in jhana.
In AN 4.123 and AN 4.124 below, it is stated that one who enters jhana, has withdrawn from sensuality and unskillful qualities.

"There is the case where an individual, withdrawn from sensuality,
  withdrawn from unskillful qualities, enters & remains in the first
  jhana: rapture & pleasure born from withdrawal, accompanied by
  directed thought & evaluation.

So, reading both parts of these suttas together, one withdraws from sensuality and unskillful qualities, and enters the first jhana, in which he can only experience the pleasure and joy dependent on what is skillful. He would not experience pleasure or joy or pain or distress from sensuality and unskillful qualities.
According to the "Manual of Buddhist Terms and Doctrines" by Nyanatiloka Mahathera, on kilesa:

'defilements', are mind-defiling, unwholesome qualities. Vis.M. XXII,
  49, 65

Since the above suttas speak of one being in the first jhana as having withdrawn from sensuality and unwholesome (unskillful) qualities, and only experience the pleasure and joy dependent on that which is wholesome (skillful), we can say that all defilements are not present in the jhana state.
Since AN 4.123 states "where an individual, withdrawn from sensuality, withdrawn from unskillful qualities, enters & remains in the first jhana", this concurs with Andrei Volkov's statement that one enters the first jhana, only AFTER withdrawing from sensuality and unskillful qualities.

user43: AN 9.36 Jhana Sutta:

"'I tell you, the ending of the mental fermentations depends on the first jhana.' Thus it has been said. In reference to what was it said? There is the case where a monk, secluded (or "withdrawn") from sensuality, secluded from unskillful qualities, enters & remains in the first jhana: rapture & pleasure born of seclusion, accompanied by directed thought & evaluation [in the following way:] He regards whatever phenomena there that are connected with form, feeling, perception, fabrications, & consciousness, as inconstant, stressful, a disease, a cancer, an arrow, painful, an affliction, alien, a disintegration, an emptiness, not-self. He turns his mind away from those phenomena, and having done so, inclines his mind to the property of deathlessness [by thinking]: 'This is peace, this is exquisite — the resolution of all fabrications; the relinquishment of all acquisitions; the ending of craving; dispassion; cessation; Unbinding.'  

AN 4.123 adds:

He savors that, finds satisfaction through that. 

AN 5.28 adds:

He permeates and pervades, suffuses and fills this very body with the rapture and pleasure born from withdrawal. There is nothing of his entire body unpervaded by rapture and pleasure born from withdrawal.
Just as if a skilled bathman or bathman's apprentice would pour bath powder into a brass basin and knead it together, sprinkling it again and again with water, so that his ball of bath powder — saturated, moisture-laden, permeated within and without — would nevertheless not drip; even so, the monk permeates, suffuses and fills this very body with the rapture and pleasure born of withdrawal. There is nothing of his entire body unpervaded by rapture and pleasure born from withdrawal...

This is why we sometimes say that kleshas are temporarily suspended while in Jhana, because you "withdraw" from them by "turning your mind away" from their objects - all the worldly pursuits, goals, and judgements.
Again, I insist: it's NOT like Jhana happens by itself and as its sideeffect brings all these good qualities. We deliberately turn away ("withdraw") from negative thoughts and we deliberately generate positive thoughts.
So it is misleading to say "all defilements are temporarily suppressed when in jhana" - we deliberately put them aside, we deliberately generate bliss - and that's how we enter jhana.

10844: <p>I've seen statements like "When one is in jhana, all defilements are suppressed temporarily." Is there any scriptural source for this?</p>
 471: <p>The closest that I can find so far, from the <a href="https://www.accesstoinsight.org/tipitaka/an/an05/an05.176.than.html" rel="nofollow noreferrer">Piti Sutta (AN 5.176)</a>:</p>

<blockquote>
  <p>[The Blessed One said:] "Excellent, Sariputta. Excellent. When a
  disciple of the noble ones enters &amp; remains in seclusion &amp; rapture,
  there are five possibilities that do not exist at that time: The pain
  &amp; distress dependent on sensuality do not exist at that time. The
  pleasure &amp; joy dependent on sensuality do not exist at that time. The
  pain &amp; distress dependent on what is unskillful do not exist at that
  time. The pleasure &amp; joy dependent on what is unskillful do not exist
  at that time. The pain &amp; distress dependent on what is skillful do not
  exist at that time. When a disciple of the noble ones enters &amp; remains
  in seclusion &amp; rapture, these five possibilities do not exist at that
  time."</p>
</blockquote>

<p>This means that only the pleasure and joy dependent on what is skillful can exist in jhana.</p>

<p>In <a href="https://www.accesstoinsight.org/tipitaka/an/an04/an04.123.than.html" rel="nofollow noreferrer">AN 4.123</a> and <a href="https://www.accesstoinsight.org/tipitaka/an/an04/an04.124.than.html" rel="nofollow noreferrer">AN 4.124</a> below, it is stated that one who enters jhana, has withdrawn from sensuality and unskillful qualities.</p>

<blockquote>
  <p>"There is the case where an individual, <strong>withdrawn from sensuality,
  withdrawn from unskillful qualities</strong>, enters &amp; remains in the first
  jhana: rapture &amp; pleasure born from withdrawal, accompanied by
  directed thought &amp; evaluation.</p>
</blockquote>

<p>So, reading both parts of these suttas together, one withdraws from sensuality and unskillful qualities, and enters the first jhana, in which he can only experience the pleasure and joy dependent on what is skillful. He would not experience pleasure or joy or pain or distress from sensuality and unskillful qualities.</p>

<p>According to the "<a href="http://www.palikanon.com/english/wtb/dic_idx.html" rel="nofollow noreferrer">Manual of Buddhist Terms and Doctrines</a>" by Nyanatiloka Mahathera, on <a href="http://www.palikanon.com/english/wtb/g_m/kilesa.htm" rel="nofollow noreferrer">kilesa</a>:</p>

<blockquote>
  <p>'defilements', are mind-defiling, unwholesome qualities. Vis.M. XXII,
  49, 65</p>
</blockquote>

<p>Since the above suttas speak of one being in the first jhana as having withdrawn from sensuality and unwholesome (unskillful) qualities, and only experience the pleasure and joy dependent on that which is wholesome (skillful), we can say that all defilements are not present in the jhana state.</p>

<p>Since AN 4.123 states "where an individual, withdrawn from sensuality, withdrawn from unskillful qualities, enters &amp; remains in the first jhana", this concurs with Andrei Volkov's statement that one enters the first jhana, only AFTER withdrawing from sensuality and unskillful qualities.</p>
 43: <p><a href="https://www.accesstoinsight.org/tipitaka/an/an09/an09.036.than.html" rel="nofollow noreferrer">AN 9.36 Jhana Sutta</a>:</p>

<blockquote>
  <p>"'I tell you, <strong>the ending of the mental fermentations <em>depends on</em> the first jhana</strong>.' Thus it has been said. In reference to what was it said? There is the case where a monk, <strong>secluded (or "withdrawn") from sensuality, secluded from unskillful qualities</strong>, enters &amp; remains in the first jhana: rapture &amp; pleasure <strong>born of seclusion</strong>, accompanied by directed thought &amp; evaluation [<strong>in the following way:</strong>] He regards whatever phenomena there that are connected with form, feeling, perception, fabrications, &amp; consciousness, as inconstant, stressful, a disease, a cancer, an arrow, painful, an affliction, alien, a disintegration, an emptiness, not-self. He <strong>turns his mind away</strong> from those phenomena, and having done so, inclines his mind to the property of deathlessness [<strong>by thinking</strong>]: 'This is peace, this is exquisite — the resolution of all fabrications; the relinquishment of all acquisitions; the ending of craving; dispassion; cessation; Unbinding.'  </p>
</blockquote>

<p><a href="https://www.accesstoinsight.org/tipitaka/an/an04/an04.123.than.html" rel="nofollow noreferrer">AN 4.123</a> adds:</p>

<blockquote>
  <p>He <strong>savors</strong> that, finds satisfaction through that. </p>
</blockquote>

<p><a href="https://www.accesstoinsight.org/ati/tipitaka/an/an05/an05.028.than.html" rel="nofollow noreferrer">AN 5.28</a> adds:</p>

<blockquote>
  <p>He <strong>permeates and pervades</strong>, suffuses and fills this very body <strong>with the rapture and pleasure</strong> born from withdrawal. There is nothing of his entire body unpervaded by rapture and pleasure born from withdrawal.</p>
  
  <p>Just as if a skilled bathman or bathman's apprentice would pour bath powder into a brass basin and knead it together, sprinkling it again and again with water, so that his ball of bath powder — saturated, moisture-laden, permeated within and without — would nevertheless not drip; even so, the monk permeates, suffuses and fills this very body with the rapture and pleasure born of withdrawal. There is nothing of his entire body unpervaded by rapture and pleasure born from withdrawal...</p>
</blockquote>

<p>This is why we sometimes say that kleshas are temporarily suspended while in Jhana, because you "withdraw" from them by "turning your mind away" from their objects - all the worldly pursuits, goals, and judgements.</p>

<p>Again, I insist: it's NOT like Jhana happens by itself and as its sideeffect brings all these good qualities. We deliberately turn away ("withdraw") from negative thoughts and we deliberately generate positive thoughts.</p>

<p>So it is misleading to say "all defilements are temporarily suppressed when in jhana" - we deliberately put them aside, we deliberately generate bliss - and that's how we enter jhana.</p>
