Śatapatha Brāhmaṇa ("of a hundred paths") 3.4.3.3

3.4.3.3

so 'gninaiva tvacaṃ vipalyaṅgayate | tapo vā agnistapo dīkṣā tadavāntarāṃ dīkṣāmupaiti saṃtarāmaṅgulīracate saṃtarām mekhalām paryastāmevaināmetatsatīm paryasyate prajāmu haiva taddevā upāyan

By means of the fire they (the priests) envelop him with a skin. Now, fire being fervour, and the consecration being fervour, he thereby undergoes an intermediate consecration. He turns in his fingers more tightly and draws the zone tighter, whereby he (again) puts round himself what was put round him before. Moreover, it was offspring the gods thereby obtained.