Śatapatha Brāhmaṇa ("of a hundred paths") 4.2.3.1

4.2.3.1

ayaṃ ha vā asyaiṣo 'nirukta ātmā yadukthyaḥ | so 'syaiṣa ātmaivātmā hyayamaniruktaḥ prāṇaḥ so 'syaiṣa āyureva tasmādanayā gṛhṇātyasyai hi sthālī bhavati sthālyā hyenaṃ gṛhṇātyajarā hīyamamṛtājaraṃ hyamṛtamāyustasmādanayā gṛhṇāti

That Ukthya (graha), forsooth, is his undefined breath (vital air), and as such it is that self of his; for the undefined breath is the self; it is his vital energy. Hence he draws it by means of this (earth), because of her is the bowl, and he draws it with a bowl;--for undecaying and immortal is this (earth), and undecaying and immortal is the vital energy; therefore he draws it by means of this (earth or bowl).