Śatapatha Brāhmaṇa ("of a hundred paths") 2.5.1.3

2.5.1.3

so 'rcañcrāmyanprajāpatirīkṣāṃ cakre | kathaṃ nu me prajāḥ sṛṣṭāḥ parābhavantīti sa haitadeva dadarśānaśanatayā vai me prajāḥ parābhavantīti sa ātmana evāgre stanayoḥ paya āpyāyayāṃ cakre sa prajā asṛjata tā asya prajāḥ sṛṣṭā stanāvevābhipadya tāstataḥ sambabhūvustā imā aparābhūtaḥ

While praising and practising austerities, Pragâpati thought within himself, 'How comes it that the living beings created by me pass away?' He then became aware that his creatures passed away from want of food. He made the breasts in the fore-part of (their) body teem with milk. He then created living beings; and by resorting to the breasts, the beings created by him thenceforward continued to exist: they are these (creatures) which have not passed away.