Mahas is Brahman. All the Vedas are increased by the Brahman. Bhu is Prana (up-breathing), Bhuvas is Apana, (down-breathing), Suvas is Vyana (back-breathing). Mahas is food. All breathings are increased by food. Thus there are these four times four, the four and four sacred interjections. He who knows these, Knows the Brahman. All Devas bring offerings to him.

In plain words: Mahas is Brahman, the ultimate reality, and it makes all the Vedas, the sacred texts, great. The three other words stand for three kinds of breath in the body, and Mahas is food, which keeps all breathing going. Whoever understands these four groups of four knows Brahman, and all the gods honor that person.