At Sāvatthi.

"Just as, bhikkhus, a water pot without a stand is easily knocked over, but [a water pot] with a stand is hard to overturn; so too, bhikkhus, a mind without support is easily knocked over, but [a mind] with support is hard to overturn.

And what, bhikkhus, is the support for the mind? It is this very Noble Eightfold Path, namely: right view, right intention, right speech, right action, right livelihood, right effort, right mindfulness, and right concentration. This is the support for the mind.

Just as, bhikkhus, a water pot without a stand is easily knocked over, but [a water pot] with a stand is hard to overturn; so too, bhikkhus, a mind without support is easily knocked over, but [a mind] with support is hard to overturn."