There are three divisions of dharma: The first comprises sacrifices, study, and charity; the second consists of austerities, such as fasting; and the third is the life of celibacy and living with the teacher in his house till death. People devoted to these three divisions of dharma go to Swarga-loka after death. But one who is devoted to Brahman attains immortality.
Prajāpati (i.e., Virāṭ) thought about the worlds (he would have). Out of his thinking, the three Vedas took shape. He then began to think about the Vedas. As a result of this thinking, the Vedas gave birth to the three vyāhṛtis: bhūḥ, bhuvaḥ, and svaḥ.
(Prajāpati then) meditated on those three vyāhṛtis (bhūḥ, bhuvaḥ, and svaḥ). Out of the vyāhṛtis, which he thought about, emerged Oṃkāra. Just as a network of ribs is spread all over a leaf, similarly, Oṃkāra permeates every form of speech (or, everything). All this is Oṃkāra. All this is Oṃkāra.