user23952: 
As the Buddha says, "What a person considers and reflects upon for a
long time, to that his mind will bend and incline."

The above quote is from Nyanaponika Thera, found here at Access to Insight.
Does anyone know where the Buddha says that, in the Pali Canon?
A google search of the quote was not helpful.

user471: It's from here:

"Whatever a monk keeps pursuing with his thinking & pondering, that
becomes the inclination of his awareness.
MN 19 (translated by Ven. Thanissaro)


“Bhikkhus, whatever a bhikkhu frequently thinks and ponders upon, that
will become the inclination of his mind.
MN 19 (translated by Ven. Bodhi)


Whatever a mendicant frequently thinks about and considers becomes
their heart’s inclination.
MN 19 (translated by Ven. Sujato)


23952: <blockquote>
<p>As the Buddha says, &quot;What a person considers and reflects upon for a
long time, to that his mind will bend and incline.&quot;</p>
</blockquote>
<p>The above quote is from Nyanaponika Thera, found <a href="https://www.accesstoinsight.org/lib/authors/nyanaponika/wheel006.html#:%7E:text=Meditative%20development%20of%20the%20sublime%20states%20will%20be%20aided%20by,mind%20will%20bend%20and%20incline.%22" rel="nofollow noreferrer">here</a> at Access to Insight.</p>
<p>Does anyone know where the Buddha says that, in the Pali Canon?</p>
<p>A <a href="https://www.google.ca/search?q=%22What%20a%20person%20considers%20and%20reflects%20upon%20for%20a%20long%20time%2C%20to%20that%20his%20mind%20will%20bend%20and%20incline.%22&amp;lr=&amp;safe=images&amp;as_qdr=all&amp;sxsrf=AJOqlzWaPNrHSlYXrghlXktMhmk5FzV3WQ%3A1673269610221&amp;ei=ahG8Y_yZDeebptQPl5G3wAk&amp;ved=0ahUKEwj89uuFx7r8AhXnjYkEHZfIDZgQ4dUDCA8&amp;uact=5&amp;oq=%22What%20a%20person%20considers%20and%20reflects%20upon%20for%20a%20long%20time%2C%20to%20that%20his%20mind%20will%20bend%20and%20incline.%22&amp;gs_lcp=Cgxnd3Mtd2l6LXNlcnAQA0oECEEYAEoECEYYAFAAWABgvQVoAHAAeACAAVCIAVCSAQExmAEAoAECoAEBwAEB&amp;sclient=gws-wiz-serp" rel="nofollow noreferrer">google</a> search of the quote was not helpful.</p>
 471: <p>It's from here:</p>
<blockquote>
<p>&quot;Whatever a monk keeps pursuing with his thinking &amp; pondering, that
becomes the inclination of his awareness.<br />
<a href="https://www.accesstoinsight.org/tipitaka/mn/mn.019.than.html" rel="nofollow noreferrer">MN 19</a> (translated by Ven. Thanissaro)</p>
</blockquote>
<blockquote>
<p>“Bhikkhus, whatever a bhikkhu frequently thinks and ponders upon, that
will become the inclination of his mind.<br />
<a href="https://suttacentral.net/mn19/en/bodhi?reference=none&amp;highlight=false" rel="nofollow noreferrer">MN 19</a> (translated by Ven. Bodhi)</p>
</blockquote>
<blockquote>
<p>Whatever a mendicant frequently thinks about and considers becomes
their heart’s inclination.<br />
<a href="https://suttacentral.net/mn19/en/sujato?layout=plain&amp;reference=none&amp;notes=asterisk&amp;highlight=false&amp;script=latin" rel="nofollow noreferrer">MN 19</a> (translated by Ven. Sujato)</p>
</blockquote>
