Jaiminīya Upaniṣad Brāhmaṇa 1.22

Just as one would pour honey into a honeycomb through honey-pipes, in the very same way that sāman poured essence back into [the ṛk].

Therefore indeed one should not accompany in singing.
Indra is he who is the udgātṛ.
Just as that one took away the essence of these, so this one takes away the essence of those.

At will, however, the sacrificer may accompany in singing, for it belongs to the sacrificer; and also a Vedic student when instructed by his teacher.

On this point, indeed, they also say: 'One should definitely accompany in singing;
for the directions accompanied in singing; thus one wins the sharing of the same world with the directions.'

Those vital breaths that are in the mouth—these very ones are the udgātṛs and the accompanying singers.
These three are the udgātṛs, and these four are the accompanying singers.

Therefore, indeed, one should appoint only four accompanying singers.
Therefore, indeed, one should touch the accompanying singers, saying: 'You are the directions; do not injure my hearing.'

That essence which existed—this very one that purifies here is that essence.

"Just as one would eat a morsel of honey," Sucitta Śailana used to say, "so should one fill oneself with this essence;
he alone, as udgātṛ, leads both himself and the sacrificer to immortality."
Third khaṇḍa in the sixth anuvāka.
The sixth anuvāka is completed.