user12223: I was once told a story by the abbott of a monastery about how the Buddha once decided to delay his speech and said it only when it was the right time.  Paraphrasing, the story is like this - 

Two tribes were going to war over the waters of a river and the Buddha
  wanted them to stop, but he knew that they were not in the right frame
  of mind to listen to him.  So he kept quiet.  After 3 days of
  fighting, when both sides were in pain from the fighting, the Buddha
  decided to give them advice at that moment, when they were primed to
  listen and they stopped the war immediately.  Although he allowed many
  people to die in waiting for the right moment, he saved a great many
  more lives.  If he had spoken right away and they'd rejected his advice, they
  might also not have listened to him afterwards either.

The abbott then advised me to remember this story as a model.  And I did.  I liked it a lot too.  This was many years ago.  The problem is, I recently decided to look up the story and found this story in the Mahāvaṃsa, of imminent war between the Sakyans and the Koliyans over the waters of the Rohini river.  A key difference here is that the Buddha did not wait until the fighting had started.  He showed up at the site where the armies had gathered.  Still a nice story of the Buddha stopping a war, but not an example of delaying speech for the appropriate moment even at some cost.
It's no longer possible for me to ask the abbott whether he meant this or another story or if he has a reference to another version of the same story which involved 3 days of battle. Instead, I'd like to ask the community about the main point:

Do you know of a canonical reference (from any flavor of Buddhism)   where the Buddha or another prominent figure decided to delay a    statement on account of timeliness and later said it with positive   impact? To be clear, instances where the Buddha decided not to say   something are numerous - I'm only looking for examples where he (or  another person) did end up saying it later.  Edit: Also, I know that the teaching on speaking at the appropriate time is quite clear - what I'm asking about is examples from the life of the ancients.
It would be particularly great if there are examples where the delay    did come at a cost.


user-1: An article (link below), an essay and the story around the intention and means on right speech, might help to understand the "Demons of defilements" in regard of certain justifications good:
Right Speech is Not Always Gentle (by Sallie B. King) - about justifying wrongs
That same issue counts as well for speaking and not speaking. Skillful and unskillful delay. But since the untrained mind is not capable to trace the real intention, the Buddha did not gave much advices there and it's not even judgeable from outside if not capable to read others mind, why one might be silent and why speaking.
It's complex but also easy when keeping it simple. Precepts just as they are without justification.
Additions on question in discussion:

Gotamist: Thank you for the answer, Bhante, and highlighting your response that the Buddha did not get into specifics in some areas. Precepts as they are, without justification is a powerful practice indeed. Thanks also for the article on social justice. Thanissaro Bhikkhu makes some excellent points there, but I was unable to see the connection you were perhaps intending to draw between the approach to social justice and my question about examples of beneficial delay.

Gotamist, never ever delay! When ever wholesome mind (wfich is actually seldom) arises, act on it. That counts not only for bodily deeds, merits, but also for speech.
If not acted, a seldom chance is gone. As the Buddha told:
Delay a little and you have lost, something that will maybe never possible to do later.

One should make haste in doing good deeds; one should restrain one's mind from evil; for the mind of one who is slow in doing good tends to take delight in doing evil.
Dhp story

If you have not told what is right, you may feel remorse a life time. Having not done even a "Duty" you will have bad conscious later.
As told in a Sutta: What ever not done at the proper time, later one will have no chance to correct. So it's really not good to delay speech, if to speak is possible. If such is censured, that lies in the sphere of those oppress.
Like my person here, if made a promis, even mental, if it was something skillful or obligated, it will follow as long as not made "real". Once told, once fullfiled, one gains release.
So beware of the "Demons of defilemts" who tell you cheating "don't do this, don't do good, they/he/she will not like good, so its bad"
There is no need of shame in regard of doing skilfull deeds, even if the whole world would laugh or blame.
If the target receiver receives? That's his/her business, luck or demerit. No need for guessing, no need to "read mind" of others. You may be wrong and at least, one does deeds for one self as long as not free from all fetters.
Speaking as well not speaking can be unskilfull and actually most staying confronted silent is very unskillful.
In regard of promises, Gotamist may maybe like to listen: [Q&A] Is changing your mind same as lying? Breaking promises
If wishing a talk and extended answer on this matter, may you feel welcome to ask for.
There is also an explaining how to generally behave, which will help here in this regard as well, since Gotamist seems to have certain of the qualities inside him, he might enjoy to read: On general good behavior.
[Note: This is a gift of Dhamma and not meant for commercial purposes or other low wordily gain by trade an exchange with it.]

user471: In the Abhaya Sutta (MN58), the Buddha taught:

(1) In the case of words that the Tathagata knows to be unfactual,
  untrue, unbeneficial (or: not connected with the goal), unendearing &
  disagreeable to others, he does not say them.
(2) In the case of words that the Tathagata knows to be factual, true,
  unbeneficial, unendearing & disagreeable to others, he does not say
  them.
(3) In the case of words that the Tathagata knows to be factual, true,
  beneficial, but unendearing & disagreeable to others, he has a sense
  of the proper time for saying them.
(4) In the case of words that the Tathagata knows to be unfactual,
  untrue, unbeneficial, but endearing & agreeable to others, he does not
  say them.
(5) In the case of words that the Tathagata knows to be factual, true,
  unbeneficial, but endearing & agreeable to others, he does not say
  them.
(6) In the case of words that the Tathagata knows to be factual, true,
  beneficial, and endearing & agreeable to others, he has a sense of the
  proper time for saying them. Why is that? Because the Tathagata has
  sympathy for living beings."


user254: There's the story of The Weaver's Daughter from a Dhammapada commentary, where the Teacher delays talking ...

The people of Alavi waited upon the Teacher and provided him with food, and when the meal was over, took his bowl and stood waiting for him to speak the words of rejoicing (with the merits of the donors). Said the Teacher, "I came here on a journey of thirty leagues for the sake of a certain maiden. As yet she finds no opportunity to be present. When she finds the opportunity to be present, I will speak the words of rejoicing." Having so said, he sat down and remained silent. Likewise his hearers also remained silent. 


12223: <p>I was once told a story by the abbott of a monastery about how the Buddha once decided to delay his speech and said it only when it was the right time.  Paraphrasing, the story is like this - </p>

<blockquote>
  <p>Two tribes were going to war over the waters of a river and the Buddha
  wanted them to stop, but he knew that they were not in the right frame
  of mind to listen to him.  So he kept quiet.  After 3 days of
  fighting, when both sides were in pain from the fighting, the Buddha
  decided to give them advice at that moment, when they were primed to
  listen and they stopped the war immediately.  Although he allowed many
  people to die in waiting for the right moment, he saved a great many
  more lives.  If he had spoken right away and they'd rejected his advice, they
  might also not have listened to him afterwards either.</p>
</blockquote>

<p>The abbott then advised me to remember this story as a model.  And I did.  I liked it a lot too.  This was many years ago.  The problem is, I recently decided to look up the story and found <a href="http://realtruthlife.blogspot.com/2012/05/maha-buddhavamsa-war-between-sakya.html#.WdXLWROGNjs" rel="nofollow noreferrer">this story in the Mahāvaṃsa</a>, of imminent war between the Sakyans and the Koliyans over the waters of the Rohini river.  A key difference here is that the Buddha <strong><em>did not</em></strong> wait until the fighting had started.  He showed up at the site where the armies had gathered.  Still a nice story of the Buddha stopping a war, but not an example of delaying speech for the appropriate moment <em>even at some cost</em>.</p>

<p>It's no longer possible for me to ask the abbott whether he meant this or another story or if he has a reference to another version of the same story which involved 3 days of battle. Instead, I'd like to ask the community about the main point:</p>

<ol>
<li><p>Do you know of a canonical reference (from <strong>any flavor of Buddhism</strong>)   where the Buddha or another prominent figure decided to delay a    statement on account of timeliness and later said it with positive   impact? To be clear, instances where the Buddha decided not to say   something are numerous - I'm only looking for examples where he (or  another person) did end up saying it later.  <strong>Edit:</strong> Also, I know that the teaching on speaking at the appropriate time is quite clear - what I'm asking about is examples from the life of the ancients.</p></li>
<li><p>It would be particularly great if there are examples where the delay    did come at a cost.</p></li>
</ol>
 -1: <p>An article (link below), <a href="http://zugangzureinsicht.org/html/lib/authors/thanissaro/wisdomoverjustice_en.html" rel="nofollow noreferrer">an essay</a> and the story around the intention and means on right speech, might help to understand the "Demons of defilements" in regard of certain justifications good:</p>

<p><strong><a href="http://sangham.net/index.php/topic,8200.0.html" rel="nofollow noreferrer">Right Speech is Not Always Gentle (by Sallie B. King) - about justifying wrongs</a></strong></p>

<p>That same issue counts as well for speaking and not speaking. Skillful and unskillful delay. But since the untrained mind is not capable to trace the real intention, the Buddha did not gave much advices there and it's not even judgeable from outside if not capable to read others mind, why one might be silent and why speaking.</p>

<p>It's complex but also easy when keeping it simple. Precepts just as they are without justification.</p>

<p><em>Additions on question in discussion:</em></p>

<blockquote>
  <p><em>Gotamist:</em> Thank you for the answer, Bhante, and highlighting your response that the Buddha did not get into specifics in some areas. Precepts as they are, without justification is a powerful practice indeed. Thanks also for the article on social justice. Thanissaro Bhikkhu makes some excellent points there, but I was unable to see the connection you were perhaps intending to draw between the approach to social justice and my question about examples of beneficial delay.</p>
</blockquote>

<p>Gotamist, never ever delay! When ever wholesome mind (wfich is actually seldom) arises, act on it. That counts not only for bodily deeds, merits, but also for speech.</p>

<p>If not acted, a seldom chance is gone. As the Buddha told:</p>

<p>Delay a little and you have lost, something that will maybe never possible to do later.</p>

<blockquote>
  <p>One should make haste in doing good deeds; one should restrain one's mind from evil; for the mind of one who is slow in doing good tends to take delight in doing evil.</p>
  
  <p><a href="http://www.zugangzureinsicht.org/html/tipitaka/kn/dhp/dhp.09.bpit_en.html#s-dhp-116" rel="nofollow noreferrer">Dhp story</a></p>
</blockquote>

<p>If you have not told what is right, you may feel remorse a life time. Having not done even a "Duty" you will have bad conscious later.</p>

<p>As told in a Sutta: What ever not done at the proper time, later one will have no chance to correct. So it's really not good to delay speech, if to speak is possible. If such is censured, that lies in the sphere of those oppress.</p>

<p>Like my person here, if made a promis, even mental, if it was something skillful or obligated, it will follow as long as not made "real". Once told, once fullfiled, one gains release.</p>

<p>So beware of the "Demons of defilemts" who tell you cheating "don't do this, don't do good, they/he/she will not like good, so its bad"</p>

<p>There is no need of shame in regard of doing skilfull deeds, even if the whole world would laugh or blame.</p>

<p>If the target receiver receives? That's his/her business, luck or demerit. No need for guessing, no need to "read mind" of others. You may be wrong and at least, one does deeds for one self as long as not free from all fetters.</p>

<p>Speaking as well not speaking can be unskilfull and actually most staying confronted silent is very unskillful.</p>

<p>In regard of promises, Gotamist may maybe like to listen: <a href="http://sangham.net/index.php/topic,8136.0.html" rel="nofollow noreferrer">[Q&amp;A] Is changing your mind same as lying? Breaking promises</a></p>

<p>If wishing a talk and extended answer on this matter, may you <a href="http://sangham.net/index.php/topic,977.0.html#post_eng" rel="nofollow noreferrer">feel welcome to ask for</a>.</p>

<p>There is also an explaining how to generally behave, which will help here in this regard as well, since Gotamist seems to have certain of the qualities inside him, he might enjoy to read: <a href="http://sangham.net/index.php/topic,60.msg1304.html#msg1304" rel="nofollow noreferrer">On general good behavior.</a></p>

<p><em>[Note: This is a gift of Dhamma and not meant for commercial purposes or other low wordily gain by trade an exchange with it.]</em></p>
 471: <p>In the <a href="http://www.accesstoinsight.org/tipitaka/mn/mn.058.than.html" rel="nofollow noreferrer">Abhaya Sutta (MN58)</a>, the Buddha taught:</p>

<blockquote>
  <p>(1) In the case of words that the Tathagata knows to be unfactual,
  untrue, unbeneficial (or: not connected with the goal), unendearing &amp;
  disagreeable to others, he does not say them.</p>
  
  <p>(2) In the case of words that the Tathagata knows to be factual, true,
  unbeneficial, unendearing &amp; disagreeable to others, he does not say
  them.</p>
  
  <p>(3) <strong>In the case of words that the Tathagata knows to be factual, true,
  beneficial, but unendearing &amp; disagreeable to others, he has a sense
  of the proper time for saying them.</strong></p>
  
  <p>(4) In the case of words that the Tathagata knows to be unfactual,
  untrue, unbeneficial, but endearing &amp; agreeable to others, he does not
  say them.</p>
  
  <p>(5) In the case of words that the Tathagata knows to be factual, true,
  unbeneficial, but endearing &amp; agreeable to others, he does not say
  them.</p>
  
  <p>(6) <strong>In the case of words that the Tathagata knows to be factual, true,
  beneficial, and endearing &amp; agreeable to others, he has a sense of the
  proper time for saying them. Why is that? Because the Tathagata has
  sympathy for living beings."</strong></p>
</blockquote>
 254: <p>There's the story of <a href="http://www.accesstoinsight.org/lib/authors/burlingame/wheel324.html#sect24" rel="nofollow noreferrer">The Weaver's Daughter</a> from a Dhammapada commentary, where the Teacher delays talking ...</p>

<blockquote>
  <p>The people of Alavi waited upon the Teacher and provided him with food, and when the meal was over, took his bowl and stood waiting for him to speak the words of rejoicing (with the merits of the donors). Said the Teacher, "I came here on a journey of thirty leagues for the sake of a certain maiden. As yet she finds no opportunity to be present. When she finds the opportunity to be present, I will speak the words of rejoicing." Having so said, he sat down and remained silent. Likewise his hearers also remained silent. </p>
</blockquote>
