Shatapatha Brahmana 4.4.5.23

4.4.5.23

athābhyavetya snātaḥ | anyo 'nyasya pṛṣṭhe pradhāvatastāvanye vāsasī paridhāyodetaḥ sa yathāhistvaco nirmucyetaivaṃ sarvasmātpāpmano nirmucyate tasminna tāvaccanaino bhavati yāvatkumāre 'dati sa yenaiva niṣkrāmanti tena punarāyanti punaretyāhavanīye samidhamabhyādadhāti devānāṃ samidasīti yajamānamevaitayā saminddhe devānāṃ hi samiddhimanu yajamānaḥ samidhyate

Thereupon both (the sacrificer and his wife) having descended, bathe, and wash each other's back. Having wrapped themselves in fresh garments they step out: even as a snake casts its skin, so does he cast away all his sin,--there is not in him even as much sin as there is in a toothless child. By the same way by which they came out (from the sacrificial ground), they return thither; and, having returned, he puts a kindling-stick on the Âhavanîya (at the front hall-door) with, 'Thou art the kindler of the gods!' He thereby kindles the sacrificer himself, for along with the kindling of the gods the sacrificer is kindled.