Because it carries equally these two oblations, the out-breathing and the in-breathing, the Samâna is he (the Hotri priest). The mind is the sacrificer, the Udâna is the reward of the sacrifice, and it leads the sacrificer every day (in deep sleep) to Brahman.

In plain words: The comparison goes on: one breath balances breathing out and in, like a priest making offerings. The mind is the one offering the worship. Another breath, the upward breath, is the reward, because each night in deep sleep it carries the mind to Brahman, the highest reality.