Pemasutta 12.2

12.2

Idha, bhikkhave, bhikkhu akkosantaṃ na paccakkosati, rosantaṃ na paṭirosati, bhaṇḍantaṃ na paṭibhaṇḍati.

It’s when someone abuses, annoys, or argues with a mendicant, and the mendicant doesn’t abuse, annoy, or argue back at them.