Śatapatha Brāhmaṇa ("of a hundred paths") 4.4.1.1

4.4.1.1

mano ha vā asya savitā | tasmātsāvitraṃ gṛhṇāti pāṇo ha vā asya savitā tamevāsminnetatpurastātprāṇaṃ dadhāti yadupāṃśu gṛhṇāti tamevāsminnetatpaścātprāṇaṃ dadhāti yatsāvitraṃ gṛhṇāti tāvimā ubhayataḥ prāṇau hitau yaścāyamupariṣṭādyaścādhastāt

Savitri, forsooth, is his mind: therefore he draws the Sâvitra cup. And, forsooth, Savitri is his breath (vital air);--when he draws the Upâmsu cup, then he puts into him that vital air in front; and when he draws the Sâvitra cup, then he puts into him that vital air behind: thus those two vital airs on both sides are beneficial (or, put into him), both that which is above and that which is below.