A kind of Prāyaścitta (expiation);
special Pratyākhyāna (1) (formal resolve (vow) of abstinence)) prescribed in the form of expiation.
catuḥkalyāṇakaṃ prāyaścittaṃ......catvāri caturthabhaktāni catvānjācāmlāni catvāri ekasthanāni...
(BṛBhā 5360 Vṛ)
kalyāṇakaṃ prāyaścittaṃ dīyate.
(ONi 358 Vṛ Pa 296)