Jaiminīya (Talavakāra) Brāhmaṇa 1.68

1.68

prajāpatirvāvedamagra āsīt
mano ha vai prajāpatirdevatā
so'kāmayata bahuḥ syāṃ prajāyeya bhūmānaṃ gaccheyamiti
sa śīrṣata eva mukhatastrivṛtaṃ stomamasṛjata gāyatrīṃ chando rathantaraṃ sāmāgniṃ
devatāṃ brāhmaṇaṃ manuṣyamajaṃ paśum
tasmādbrāhmaṇo gāyatrīchandā āgneyo devatayā
tasmādu mukhaṃ prajānām
mukhāddhyenamasṛjata
so'kāmayata praiva jāyeyeti
sa bāhubhyāmevorasaḥ pañcadaśaṃ stomamasṛjata triṣṭubhaṃ chando bṛhatsāmendraṃ devatāṃ
rājanyaṃ manuṣyamaśvaṃ paśum
tasmādrājanyastriṣṭupchandā ṣandro devatayā
tasmādu bāhubhyāṃ vīryaṃ karoti
bāhubhyāṃ hyenamuraso vīryādasṛjata
so'kāmayata praiva jāyeyeti

Prajāpati alone was here in the beginning.
Prajāpati the deity is indeed mind.
He desired: ‘May I become many, may I propagate, may I attain abundance.’
From his head, from his mouth, he created the ninefold stoma, the Gāyatrī meter, the Rathantara sāman, Agni among deities, the Brahmin among men, the goat among animals.
Therefore the Brahmin has the Gāyatrī meter and is of the nature of Agni by deity;
and therefore he is the mouth of creatures,
for he created him from his mouth.
He desired: ‘May I propagate further.’
From his arms, from his chest, he created the fifteenfold stoma, the Triṣṭubh meter, the Bṛhat sāman, Indra among deities, the Rājanya among men, the horse among animals.
Therefore the Rājanya has the Triṣṭubh meter and is of the nature of Indra by deity;
and therefore he performs vital power with his arms,
for he created him from his arms, from the chest, from vital power.
He desired: ‘May I propagate further.’