Kauṣītaki (Śāṅkhāyana) Brāhmaṇa 21.1.6

21.1.6

jyotiḥ ṣaṣṭham ahaḥ punaḥ parastāt paryāsyan mṛtyor eva pāpmano na anvavāyanāya /

xxi. 1. The gods, desirous of smiting away death, the evil, and desiring identity of world and union with Brahman, saw this Abhiplava six-day (rite); by this Abhiplava they approach, and having smitten away death, the evil, obtained identity of world and union with Brahman; verily thus also the sacrificers approach by the Abhiplava, and having smitten away death, the evil, obtain identity of world and union with Brahman. Having approached with the first set of three days, they sacrificed on the fourth day with the Go, for going; they performed the Āyus as the fifth day, to secure full life; the Jyotis as the sixth day they put around behind again, to prevent evil following after.