Jaiminīya (Talavakāra) Brāhmaṇa 37.214

37.214

athagāyatrapārśvam
ime vai lokā gāyatrapārśvam
eṣveva tallokeṣu pratitiṣthanti
devā vai svargakāmāstapo'tapyanta
ta etatsāmāpaśyan
tenāstuvata
tadenāngāyatrameva bhūtvā svargaṃ lokamavahat
te'bruvansvargaṃ lokaṃ gatvā gāyatraṃ vāva no'sya sāmnaḥ pakṣāvabhūtāmiti
tadeva gāyatrapakṣasya gāyatrapakṣatvam
gāyatrapakṣaṃ ha vai nāmaitat
tadgāyatrapārśvamityākhyāyate
taddhiṃkāravadbhavatyannādyasya pratthyai
hiṃkāravadbhirvai prajāpatiḥ prajābhyo'nnādyaṃ prāyacchat
prāsmā annādyaṃ dīyate ya evaṃ veda

Then the Gāyatrapārśva.
These worlds indeed are the Gāyatrapārśva;
thus they are firmly established in these worlds.
The gods indeed, desiring heaven, practiced austerity.
They saw this sāman.
With it they praised.
Becoming the Gāyatra itself, it conveyed them to the heavenly world.
Having gone to the heavenly world, they said: "The Gāyatra indeed has become the two wings of this sāman of ours."
That is the "Gāyatra-wingedness" of the Gāyatrapakṣa.
It was indeed named Gāyatrapakṣa;
it is [now] called Gāyatrapārśva.
It contains the hiṃ-sound, for the extension of food.
With [sounds] containing hiṃ, Prajāpati gave food to the creatures.
Food is given to him who knows thus.