Śaṅkaraon Brahma Sūtra 3.4.42

Some teachers, however, are of opinion that the transgression of the vow of chastity, even on the part of a professed BrahmaMrin, is a minor sin, not a mortal one, excepting cases where the wife of the teacher and so on are concerned. For they plead that that sin is not anywhere enumerated among the deadly ones such as violating a teacher’s bed and so on. Accordingly they claim the expiatory ceremony to be valid for the Naish///ika as well as the Upakurva/^a ; both being alike Brahma/fcarins and having committed the same offence. The case is analogous to that of eating. Just as Brahma^^^rins (in general) who have broken their vow by eating honey, flesh, and the like may again purify themselves by a ceremony, so here also. The reason for this decision is that for those who assume the absence of all expiation on the part of the Naish^/nkas no scriptural passage supporting their view is met with; while those who admit expiation can base their view on the passage quoted above (‘ A student who has broken the vow’ &c.), which makes no distinction between Upakurva/;as and Naish/Znkas. It therefore is more appropriate to assume the validity of the ceremony for Naish/Zdkas also. The principle guiding the decision has been explained in the chapter treating of the means of right knowledge (Ptj. Mi. Sfl. I, 3, 8).—On this view the SmWti-passage which declares that there is no expiation for the Naish/Z/ika must be explained as aiming at the origination of weighty effort on the NaishZZdka’s part.—Similarly in the case of the mendicant and the hermit. The hermit, when he has broken his vows, undergoes the KrU'^Z^ra penance for twelve nights and then cultivates a place rich in plants. The mendicant proceeds like the hermit, with the exception of cultivating the Soma-plant, and undergoes the purifications prescribed for his state. The rules given by SmrZti for those cases have to be followed.