Shatapatha Brahmana 8.3.4.14

8.3.4.14

tadyāḥ sapta purastādvālakhilyā upadadhāti | ya eveme sapta purastātprāṇāstānasminnetaddadhāti tā anantarhitā etābhyo daśabhya upadadhātyanantarhitāṃstacīrṣṇaḥ prāṇāndadhāti

And the seven (Vâlakhilyâs) which he places in front are these seven vital airs here in the forepart (of an animal): it is these he thus puts into him (Agni). He places them so as not to he separated from those ten (Prânabhrits): he thereby puts in vital airs that are not separate from the head.