Śatapatha Brāhmaṇa ("of a hundred paths") 4.4.1.4

4.4.1.4

taṃ vā upāṃśupātreṇa gṛhṇāti | mano ha vā asya savitā prāṇa upāṃśustasmādupāṃśupātreṇa gṛhṇātyantaryāmapātreṇa vā samānaṃ hyetadyadupāṃśvantaryāmau prāṇodānau hi

He draws it with the Upâmsu vessel. For Savitri is his mind, and the Upâmsu is his breath: therefore he draws it with the Upâmsu vessel; or with the Antaryâma vessel, for that is one and the same, since the Upâmsu and Antaryâma are the out-breathing and in-breathing.