Śatapatha Brāhmaṇa ("of a hundred paths") 10.4.1.3

10.4.1.3

taṃ nidadhāti vauṣaḍiti vaugiti vā eṣa ṣaḍitīdaṃ ṣaṭcitikamannaṃ kṛtvāsmā apidadhātyātmasammitaṃ yadu vā ātmasammitamannaṃ tadavati tanna hinasti yadbhūyo hinasti tadyatkanīyo na tadavati

He places him (the Ukhya Agni, on the fire-altar) with 'Vaushat!' for 'vauk' is he (Agni), and 'shat (six)' is this six-layered food: having prepared it, he offers it to him as proportionate to this body, for food which is proportionate to the body satisfies, and does not injure it; but when there is too much, it does injure it, and when there is too little, it does not satisfy it.