Jaiminīya (Talavakāra) Brāhmaṇa 1.136

Hunger is indeed the chariots, and food is the Rathantara.
With food they slay hunger.
Having slain hunger after hunger with food, they mounted up to the heavenly world.
With the Bṛhat the gods wished to go to the heavenly world.
With it they did not reach it.
To it they added an Uṣṇih and a Kakubh.
With it they reached it.
Having gone to the heavenly world, they said: 'Great (bṛhat) indeed has this become, by which we reached the heavenly world.'
That is the Bṛhat-nature of the Bṛhat.
One desiring the heavenly world should climb the twelve ascents of the Bṛhat; one desiring rain should make the ocean roar.
As many syllables as there are of the Bṛhat, the Uṣṇih, and the Kakubh, so far from here is the heavenly world.
He reaches the heavenly world, who knows thus.

Now the Bṛhat.

Mind is the Bṛhat.

The prelude consists of twelve syllables.

For so great is the sāman.

Twelve months are the year.

The year is the sāman.

The three ascents of the Bṛhat are these worlds.

They become nine again; [they are] the breaths themselves.