Jaiminīya (Talavakāra) Brāhmaṇa 1.72

Seated facing west, the Prastotṛ chants the prastāva;
he thereby bestows vigor upon the western quarter.
Seated facing south, the Pratihartṛ chants the pratihāra;
he thereby bestows vigor upon the southern quarter.
The other officiating priests perform their office facing east;
they thereby bestow vigor upon the eastern quarter.
Therefore this quarter is the most full of vital power, the most supportive of life, enjoyed by the greatest number.
Therefore, when creatures go into destitution, they go toward the east;
for this quarter is the most full of vital power, the most supportive of life, enjoyed by the greatest number.
Since the Udgātṛs have the north as their deity, why then, they ask, do they perform the priestly office turning around to the [different] quarters?
He should say: 'For the conquest of the quarters, for the attainment of the quarters.'
Therefore food is found in all the quarters.
'Prop up the sky, fill the atmosphere, make the earth firm with your lower part!
May Dyutāna Māruta set you up according to the firm law of Mitra and Varuṇa!
Fill heaven and earth with clarified butter!
Make the plants bear good fruit, svāhā!' — thus he offers upon the audumbarī post.
He thereby anoints these worlds with essence.

Prajāpati created creatures.

He also desired to create Agni from his mouth.

That Agni, shrinking back in disgust from the mouth, running upward, was created, having struck out his brain.

The gods and the ṛṣis, having gathered, said: 'This struck brain must not become useless; let us make this

into some sacred heap.'

They said to Bṛhaspati: 'Draw the Soma into this!'

That Bṛhaspati said: 'Indeed, this is cruel, unpurified, unfit for sacrifice, raw.'

They said: 'We shall make it purified, fit for sacrifice, cooked for you.'

'Then bring it to me!'

'So be it.'

They gave it to him.