Aitareyabrahmana 2.15

2.15

The Adhvaryu says: 'Hotṛ priest, recite for the morning-traveling gods.'
These indeed are the morning-traveling gods: Agni, Uṣas, and the two Aśvins.
They come with seven metres each.
The morning-traveling gods come to the call of him who knows this.
When Prajāpati himself was the Hotṛ priest about to recite the morning litany,
both the gods and the Asuras came to the sacrifice, [thinking:]
'He will recite for us; he will recite for us.'
He recited only for the gods.
Thence the gods flourished, and the Asuras perished.
He flourishes in himself, and his hateful, evil rival perishes, who knows this.
He recited it for the gods in the morning. In that he recited it in the morning,
that is the morning-litany-ness of the morning litany.
It should be recited in the deep night, for the grasping of all speech, of all brahman.
Whoever flourishes, whoever attains superiority, after his speech, when uttered, others speak.
Therefore it should be recited in the deep night.
It should be recited before speech is uttered.
If he were to recite it when speech had already been uttered, he would make him merely repeat what another has uttered.
Therefore it should be recited in the deep night.
He should recite it before the crying of birds.
The birds, the fowls, are indeed the mouth of Nirṛti.
In that he recites before the crying of birds, [he thinks:]
'May we not speak after unholy speech has been uttered.' Therefore it should be recited in the deep night.
On the other hand, he should recite only when the Adhvaryu gives the impulse.
When the Adhvaryu gives the impulse, he gives it with speech, and with speech the Hotṛ recites;
for speech is brahman. The desire that is in speech and in brahman is obtained there.