CC Madhya 22.143
kṛṣṇa tāṅre śuddha kare, nā karāya prāyaścitta
“If, however, a devotee accidentally becomes involved in a sinful activity, Kṛṣṇa purifies him. He does not have to undergo the regulative form of atonement.
Kṛṣṇa purifies from within as the caittya-guru, the spiritual master within the heart. This is described in the following verse from Śrīmad-Bhāgavatam (11.5.42).