Next follows the Uktha. Verily, breath (prana) is Uktha, for breath raises up (utthapayati) all this. From him who knows this, there is raised a wise son, knowing the Uktha; he obtains union and oneness with the Uktha.

In plain words: Breath is the Uktha, a sacred hymn, because breath raises everything up. Whoever knows this will have a wise son and becomes one with the Uktha.