Jaiminīya Upaniṣad Brāhmaṇa 3.13

'hum bhā'—for one who desires spiritual lustre;
for spiritual lustre shines [bhāti], as it were.

'hum bo'—for one who desires cattle;
for cattle low as 'bo'.

'hum bag'—for one who desires prosperity;
for people praise prosperity as 'bag'.

'hum bhā ovā'—this is the accompanying singing.

'One should sing bringing it around as if large,' said Nāka, 'one becomes of a great community, of a great settlement.'
That is just as if one, having fixed a post, should go around on this side or that side.

And regarding this, Śāṭyāyani said: 'For what desire would he fix a post?
This is merely accompanying singing;
he should pay no heed to this.'

So much for the hiṅkāras.
Now then concerning the finale [nidhana] alone:
'ovā'—these are two syllables.
The finale is the end of the sāman, heaven is the end of the worlds, the highest region of the sun is the end.

By this syllable om, the udgātṛ places that sacrificer at the end, in the heavenly world.

Whoever, being wingless, goes to the top of a tree, falls down from there;
but when a winged [bird] sits on a treetop, on the edge of a sword, on the edge of a razor, it does not fall down from there,
for it sits held firmly by its two wings.

By this syllable om, having given him wings of sound [svara], the udgātṛ places that sacrificer at the end, in the heavenly world.
Just as a winged [bird] would sit without fear, even so he sits without fear in the heavenly world, and then moves about.

These two syllables are the world of the gods and the world of human beings;
and these two syllables are the sun and the moon.

The sun is the world of the gods; the moon is the world of human beings.
Om is the sun; 'vāc' is the moon.

By this syllable om, the udgātṛ makes that sacrificer reach the sun, the world of the gods.
Third khaṇḍa in the third anuvāka.