四分律刪繁補闕行事鈔 1.133

1.133

前之四僧，若取能秉法名僧，四人實辨一切羯磨；今隨事用，故須三別。又前四人若據自行，以成僧體，並須清淨；以犯小罪，不應羯磨故。

Regarding the aforementioned four types of saṃgha, if we define the saṃgha in terms of those who can perform the procedure, four persons can in fact execute all types of karman; yet following the practical affairs for which they are employed, three distinctions are required. Furthermore, regarding the aforementioned four persons, if considered according to their own personal practice to constitute the essence of the saṃgha, they must all be pure, because one who has committed a minor offense must not perform a karman.