Kumārakasutta

ud5.4:2.1 Then the Buddha robed up in the morning and, taking his bowl and robe, entered Sāvatthī for alms.

ud5.4:2.2 He saw the boys tormenting the fish.

ud5.4:2.3 He went to them and said,

ud5.4:2.4 “Boys, do you fear pain? Do you dislike pain?”

ud5.4:2.5 “Yes, sir,” they replied. “We dislike pain.”