Thus have I heard:
One time, the Budha was staying at Anaathapindidas Ashrama in Jetavana of Shraavastii.
Then the Bhagavaan addressed the Bhikshus: “I continually observe the thoughts in one person’s mind—this person falls into naraka as quickly as one bends and straightens an arm. Why so? Because of his evil mind. When the mind becomes diseased, it leads to falling into naraka.”
Then the Bhagavaan spoke this verse:
“Just as a person harbors hateful thoughts,
I now declare to all bhikshus, explaining its meaning in full.
Now is precisely the time—if one were to die,
even entry into naraka would stem from the mind’s impure actions.
“Therefore, bhikshus! Subdue your minds and cease impure actions. Thus, bhikshus, should you train.”
When the bhikshus heard what the Budha said, they followed it with joy.