Jaiminīya (Talavakāra) Brāhmaṇa 2.253

Now, as it were quietly, as it were without sound, great delight is born.
And this is the truth, which is the gāyatra.
One would confound its proper form if one were to repeat it with the character of the rathantara.
Therefore it should be sung without sound.
Now the ājya [stotra] for Agni has one deity.
It is departure.
Then that for Mitra and Varuṇa has two deities.
It is stability.
Then that for Indra has one deity.
It is departure.
Then that for Indra and Agni has two deities.
That is both departure and stability.
He attains stability who knows thus.
By the threefold and fifteen-fold [stomas] a man is established in this world.
The [foot] which he lifts is the threefold; that with which he stands is the fifteen-fold.
These two are both threefold and both fifteen-fold.
Brilliance and spiritual luster are the threefold stoma; force and vital power are the fifteen-fold.
Having stood firm with force and vital power, he carries off brilliance and spiritual luster, who knows thus.

Now the gāyatrī of the midday pavamāna:

this downward breath—that is it.

On it there are two sāmans.

Therefore with this breath one does two things: one produces feces and passes wind.

There are different preludes and different final choruses, with the hiṃ-sound between them.

Therefore the one does not sound along with the other, nor the other with the one.

For by this it is kept distinct.

Then the bṛhatī:

this forward breath—that is it.

On it there are two sāmans.

Therefore with this breath one does two things: one emits semen and urinates.

There are different preludes and different final choruses, with the hiṃ-sound between them.

Therefore the one does not sound along with the other, nor the other with the one.

For by this it is kept distinct.

Then the triṣṭubh:

that is the navel.

On it there is one sāman.

Therefore with this breath one does only one thing: that one breathes out in accord with the out-breathing breaths.

Now the pṛṣṭha [stotras]:

the pṛṣṭhas are faculty and vital power.

Therefore, of whatever possesses a spine—an ox, a horse, a man—their spine is the strongest.

For faculty and vital power are the pṛṣṭhas.

They are [chanted] on bṛhatī verses.

Therefore these ribs, like bṛhatīs, and these cattle, like bṛhatīs, come together to the back.

Now the gāyatrī of the ārbhava pavamāna:

this breath—that is it.

On it there are two sāmans.

Therefore with the breath one does two things: one breathes in and breathes out.

There are different preludes and different final choruses, with the hiṃ-sound between them.

Therefore the one does not sound along with the other, nor the other with the one.

For by this it is kept distinct.

Then the uṣṇih and the kakubh:

they are the two eyes.

The meter is the same.

There are two sāmans.

Therefore the two eyes see the same [thing].

They are composed of three-footed verses.

Therefore, the eye is threefold: the white, the black, and the pupil.

They are on two verses that are increasingly wider.

Therefore, a person sees increasingly further.

There is a different prastāva, a different nidhana, and the sound hiṃ in between.

Therefore, the two eyes have different vital powers.

Then the Anuṣṭubh.

That is speech itself.

On it are two sāmans.

Therefore, one does two things with speech: eats food with it and speaks.

There is a different prastāva, a different nidhana, and the sound hiṃ in between.

Therefore, one does not speak everything as truth with speech, nor everything as untruth.

For it is distributed by this.

Then the Jagatī.

That is the ear itself.

On it is one sāman.

Therefore, one does only one thing with this ear, which is merely to hear.

It is on a four-footed verse.

Therefore, being in the same place, one hears in all directions.

Even when facing away, one hears someone speaking from behind.

Then the Yajñāyajñīya.

That is the head itself.

For the head is placed upon the other limbs.

The Yajñāyajñīya is elevated above the other chants.

He who knows thus becomes elevated above his own people.

The head is indeed higher than the other limbs.

The Yajñāyajñīya is higher than the other chants.

He who knows thus becomes higher than his own people.

This sacrifice, with evil dispelled, is truly perceptible.