Ariyavamsasutta 1.5

1.5

Yo hi tattha dakkho analaso sampajāno patissato, ayaṃ vuccati, bhikkhave, bhikkhu porāṇe aggaññe ariyavaṃse ṭhito.

A mendicant who is deft, tireless, aware, and mindful in this is said to stand in the ancient, primordial noble custom.