Visuddhimagga II-5

Bhikkhāsaṅkhātānaṃ pana āmisapiṇḍānaṃ pātoti piṇḍapāto, parehi dinnānaṃ piṇḍānaṃ patte nipatananti vuttaṃ hoti.

（三）称为施食的团食落下为乞食，即他人所施的团食集于钵中的意思。

Ñ(II,5): iii. The dropping (pāta) of the lumps (piṇḍa) of material sustenance (āmisa) called alms (bhikkhā) is 'alms food' (piṇḍapāta); the falling (nipatana) into the bowl of lumps (piṇḍa) given by others, is what is meant.

Taṃ piṇḍapātaṃ uñchati taṃ taṃ kulaṃ upasaṅkamanto gavesatīti piṇḍapātiko.

到各户人家去求食者为乞食者；

Ñ: He gleans that alms food (that falling of lumps), he seeks it by approaching such and such a family, thus he is called an 'alms-food [eat-]er' (piṇḍapātika).

Piṇḍāya vā patituṃ vatametassāti piṇḍapātī, patitunti carituṃ, piṇḍapātī eva piṇḍapātiko. Piṇḍapātikassa aṅgaṃ piṇḍapātikaṅgaṃ.

或誓愿行乞团食者为乞食者。行即是走。乞食者即乞食的人。他的支分为「常乞食支」。

Ñ: Or his vow is to gather (patituṃ) the lump (piṇḍa), thus he is a 'lump-gatherer' (piṇḍapātin). To 'gather' is to wander for. A 'lump-gatherer' (piṇḍapātin) is the same as an 'alms-food-eater' (piṇḍapātika). The practice of the alms-food-eater is the 'alms-food-eater's practice'.