user23952: I'm not sure how to understand the sixth reward, or even who is rewarded. Can someone explain it?
(AN 6:103, from https://www.dhammatalks.org/suttas/AN/AN6_103.html, complete sutta quoted below)
“In seeing six rewards, it’s enough for a monk to establish the perception of stress with regard to all fabrications without exception. Which six? ‘The perception of disenchantment1 will be established within me with regard to all fabrications, like a murderer with a drawn sword. My mind will rise above every world. I’ll become one who sees peace in unbinding. My obsessions2 will go to their destruction. I’ll be one who has completed his task. The Teacher will have been served with goodwill.’
“In seeing these six rewards, it’s enough for a monk to establish the perception of stress with regard to all fabrications without exception.”

user254: Looking on suttacentral with Pali lookup enabled:

https://suttacentral.net/an6.103/en/sujato?layout=linebyline&reference=none&notes=asterisk&highlight=false&script=latin

The text in question is,

satthā ca me pariciṇṇo bhavissati mettāvatāyā’ti

Given the mini-translation ...

sattha

a science; an art; a lore 2) a knife; a lance 3) a caravan


... I wondered how that could translate as "Teacher"?
I think that word-lookup is misleading -- the text says not sattha but rather satthā.
And frankk's answer says that's sathhar, "teacher, master" (which, i.e. satthar and satthā being the same word, is very possible because in Pali word-endings change when nouns are declined).
The full PTS dictionary mentions ...

[cp. Vedic śāstra, fr. śās to teach] a science, art, lore

... so that's the root or etymology of the word.

The question of "who the teacher is?" is notoriously difficult to analyse -- "is the Tathagata this body?" etc. It may be worth remembering SN 6.2 which implies that even the Buddha wants or needs to "dwell in dependence, honoring and respecting [him]" which I think implies that's a motive (or a condition, a sine qua non) of any monk.
Finally the word translated reward is ānisaṁsa


profit, advantage; benefit, blessing (in, locative)
praise i.e. that which is commendable, profit, merit, advantage good result, blessing in or from (c. loc.). There are five ānisaṁsā sīlavato sīla-sampadāya or blessings which accrue to the virtuous, enumerated at ...


So maybe not a mundane "reward" but more generally something praise-worthy (or I might say blameless).

user16297: satthar 1
masc. master; teacher [√sās + tar] ●
satthar 2
masc. name of a privately enlightened Buddha; lit. teacher [√sās + tar] ●
In the suttas, "sattha" is often referring to The Buddha.
The "reward", is that the disciples feel gratitude for the Buddha, and by practicing his teaching to its culmination is the ultimate sign of respect and gratitude, and the best way to serve him.

23952: <p>I'm not sure how to understand the sixth reward, or even who is rewarded. Can someone explain it?</p>
<p>(AN 6:103, from <a href="https://www.dhammatalks.org/suttas/AN/AN6_103.html" rel="nofollow noreferrer">https://www.dhammatalks.org/suttas/AN/AN6_103.html</a>, complete sutta quoted below)</p>
<p>“In seeing six rewards, it’s enough for a monk to establish the perception of stress with regard to all fabrications without exception. Which six? ‘The perception of disenchantment1 will be established within me with regard to all fabrications, like a murderer with a drawn sword. My mind will rise above every world. I’ll become one who sees peace in unbinding. My obsessions2 will go to their destruction. I’ll be one who has completed his task. <strong>The Teacher will have been served with goodwill.</strong>’</p>
<p>“In seeing these six rewards, it’s enough for a monk to establish the perception of stress with regard to all fabrications without exception.”</p>
 254: <p>Looking on suttacentral with Pali lookup enabled:</p>
<ul>
<li><a href="https://suttacentral.net/an6.103/en/sujato?layout=linebyline&amp;reference=none&amp;notes=asterisk&amp;highlight=false&amp;script=latin" rel="nofollow noreferrer">https://suttacentral.net/an6.103/en/sujato?layout=linebyline&amp;reference=none&amp;notes=asterisk&amp;highlight=false&amp;script=latin</a></li>
</ul>
<p>The text in question is,</p>
<blockquote>
<p><em>satthā ca me pariciṇṇo bhavissati mettāvatāyā’ti</em></p>
</blockquote>
<p>Given the mini-translation ...</p>
<blockquote>
<p>sattha</p>
<ol>
<li>a science; an art; a lore 2) a knife; a lance 3) a caravan</li>
</ol>
</blockquote>
<p>... I wondered how that could translate as &quot;Teacher&quot;?</p>
<p>I think that word-lookup is misleading -- the text says not <em>sattha</em> but rather <em>satthā</em>.</p>
<p>And frankk's answer says that's <a href="https://suttacentral.net/define/satthar" rel="nofollow noreferrer">sathhar</a>, &quot;teacher, master&quot; (which, i.e. satthar and <em>satthā</em> being the same word, is very possible because in Pali word-endings change when nouns are <a href="https://en.wikipedia.org/wiki/Declension" rel="nofollow noreferrer">declined</a>).</p>
<p>The <a href="https://dsal.uchicago.edu/cgi-bin/app/pali_query.py?qs=sattha&amp;searchhws=yes&amp;matchtype=exact" rel="nofollow noreferrer">full PTS dictionary</a> mentions ...</p>
<blockquote>
<p>[cp. Vedic śāstra, fr. śās to teach] a science, art, lore</p>
</blockquote>
<p>... so that's the root or etymology of the word.</p>
<hr />
<p>The question of &quot;who the teacher is?&quot; is notoriously difficult to analyse -- &quot;is the Tathagata this body?&quot; etc. It may be worth remembering <a href="https://buddhism.stackexchange.com/a/28696/254">SN 6.2</a> which implies that even the Buddha wants or needs to &quot;dwell in dependence, honoring and respecting [him]&quot; which I think implies that's a motive (or a condition, a <em>sine qua non</em>) of any monk.</p>
<p>Finally the word translated reward is <a href="https://suttacentral.net/define/%C4%81nisa%E1%B9%81sa" rel="nofollow noreferrer">ānisaṁsa</a></p>
<blockquote>
<ol>
<li>profit, advantage; benefit, blessing (in, locative)</li>
<li>praise i.e. that which is commendable, profit, merit, advantage good result, blessing in or from (c. loc.). There are five ānisaṁsā sīlavato sīla-sampadāya or blessings which accrue to the virtuous, enumerated at ...</li>
</ol>
</blockquote>
<p>So maybe not a mundane &quot;reward&quot; but more generally something praise-worthy (or I might say blameless).</p>
 16297: <p>satthar 1
masc. master; teacher [√sās + tar] ●</p>
<p>satthar 2
masc. name of a privately enlightened Buddha; lit. teacher [√sās + tar] ●</p>
<p>In the suttas, &quot;sattha&quot; is often referring to The Buddha.
The &quot;reward&quot;, is that the disciples feel gratitude for the Buddha, and by practicing his teaching to its culmination is the ultimate sign of respect and gratitude, and the best way to serve him.</p>
