Brihadaranyaka Upanishad 3.1.10

3.1.10

yājñavalkyeti hovāca katyayamadyodgātāsminyajñe stotriyāḥ stoṣyatīti tisra iti katamāstāstisra iti puronuvākyāca yājyā ca śasyaiva tṛtīyā katamāstā yā adhyātmamiti prāṇa eva puronuvākyāpāno yājyā vyānaḥ śasyā kiṃ tābhirjayatīti pṛthivīlokameva puronuvākyayā jayatyantarikṣalokaṃ yājyayā dyulokam̐ śasyayā tato ha hotāśvala upararāma

'Yâjnavalkya,' said he, 'how many classes of hymns will the Udgâtri chant in this sacrifice to-day?' 'Three classes.' 'Which are those three?' 'The preliminary, the sacrificial, and the eulogistic hymns as the third.’ ‘Which are those that have reference to the body?’ ‘The Prâna is the preliminary hymn, the Apâna is the sacrificial hymn, and the Vyâna is the eulogistic hymn.’ ‘What does he win through them?’ ‘Through the preliminary hymns he wins the earth, through the sacrificial hymns he wins the sky, and through the eulogistic hymns he wins heaven.’ Thereupon the Hotri Ashwala kept silent.

3.1.10.p1

iti tṛtīyādhyāye prathamaṃ brāhmaṇam