BṚHADĀRAṆYAKA UPANISHAD · 3.2.2

प्राणो वै ग्रहः ।
सो ऽपानेनातिग्रहेण गृहीतः ।
प्राणेन हि गन्धाञ् जिघ्रति ॥

prāṇo vai grahaḥ ।
so ’pānenātigraheṇa gṛhītaḥ ।
prāṇena hi gandhāñ jighrati ॥

'Prâna (breath) is one Graha, and that is seized by Apâna (down-breathing) as the Atigrâha, for one smells with the Apâna.'

F. Max Müller · The Upanishads, Sacred Books of the East 15 (1884)