Bhagavatapurana 7.15.53

7.15.53

indriyāṇi manasyūrmau vāci vaikārikaṃ manaḥ /
vācaṃ varṇasamāmnāye tamoṃkāre svare nyaset /
oṃkāraṃ bindau nāde taṃ taṃ tu prāṇe mahatyamum //

52. D. By the expression 'activities as sacrifices' should be taken, the deities presiding over the gross sacrificial activities; so also "into his five senses." Here the active offering consists in contemplating each deity as being under the control of the higher one. 53. He offers these senses into the mind (full of various thoughts) and the mind produced out of Vaikarika Ahankara into Speech and Speech into the body of articulate sounds and that collection into the sacred syllable (consisting of three vowels) and that syllable into Bindu and that into Nada and Nada into Prana called Sutratman and that Prana into the perfect Brahman.