Jaiminīya (Talavakāra) Brāhmaṇa 3.8

3.8

prajāpatireṣa yadudgātā
sa etaddaśāhenaiva prajāssṛjate
tā etābhyāmeva vaiśvānarābhyāṃ vārayate'neneta upariṣṭādamunā prajānāṃ dhṛtyā
aparāvāpāya
nāsya vittaṃ paropyate ya evaṃ veda
prāṇo vai pūrvo vaiśvānaro'pāna uttaraḥ
prāṇāpānābhyāmevaitatsamṛddhyodṛcamaśnuvate
tasmādu haitayo stotreṇa supyātprāṇānnetsaṃluṃpānīti
tadu vā āhuḥ ko hāsvapnasyeśe
yadvāva prāṇo jāgarti tadeva jāgaritam
kāmameva svaptavyamiti
tadāhuryannu parama eṣa yajñakraturyadatirātraḥ kasmādetaṃ paramaṃ santaṃ prathamamupayantīti
yajñakratūnāmevāptyā iti brūyāt
ete vai sarve yajñakratavo yadagniṣṭoma uktho'tirātraḥ
tānevaitenāpnoti yo vā agniṣṭomena daśāhaṃ kalpamānaṃ veda
kalpate'smai prātassavanenaiva prathamastriyahaḥ | kalpate mādhyandinena dvitīyas
tṛtīyasavanenatṛtīyo'gniṣṭomasāmnaiva daśamamahaḥ kalpate
kalpate'smai ya evaṃ veda

The Udgātṛ is this Prajāpati. With this ten-day rite he creates creatures. With these two Vaiśvānara [days] he holds them in check: with this one from below, with that one from above, for the stability of creatures, for avoiding scattering. The wealth of him who knows thus is not scattered. The prior Vaiśvānara is the in-breath; the latter is the out-breath. Through the completeness of in-breath and out-breath they reach the conclusion. Therefore one should sleep during their chant, [saying], 'Lest I cut off the breaths.' But as to that, they say: 'Who is master of sleep? When the breath is awake, that is being awake. One may sleep at will.' Now they say: 'Since this Atirātra is the highest sacrificial rite, why do they undertake it first, being the highest?' One should say: 'For the sake of obtaining the sacrificial rites.' All these sacrificial rites indeed are the Agniṣṭoma, the Ukthya, and the Atirātra. Through this he obtains them. He who knows the ten-day rite conforming to the Agniṣṭoma: through the morning pressing the first three-day period conforms for him, through the midday pressing the second, through the third pressing the third; through the Agniṣṭoma-sāman the tenth day conforms. Things conform for him who knows thus.