The Upanishads, Part 1 (SBE01), by Max Müller, , at sacred-texts.com
1. There are three branches of the law. Sacrifice, study, and charity are the first 1,
2. Austerity the second, and to dwell as a Brahmakârin in the house of a tutor, always mortifying the body in the house of a tutor, is the third. All these obtain the worlds of the blessed; but the Brahmasamstha alone (he who is firmly grounded in Brahman) obtains immortality.
3. Pragâpati brooded on the worlds. From them, thus brooded on, the threefold knowledge (sacrifice) issued forth. He brooded on it, and from it, thus brooded on, issued the three syllables, Bhûh, Bhuvah, Svah.
4. He brooded on them, and from them, thus brooded on, issued the Om. As all leaves are attached to a stalk, so is all speech (all words) attached to the Om (Brahman). Om is all this, yea, Om is all this.
35:1 Not the first in rank or succession, but only in enumerating the three branches of the law. This first branch corresponds to the second stage, the âsrama of the householder. Austerity is meant for the Vânaprastha, the third âsrama, while the third is intended for the Brahmakârin, the student, only that the naishthika or perpetual Brahmakârin here takes the place of the ordinary student. The Brahmasamstha would represent the fourth âsrama, that of the Sannyâsin or parivrâg, who has ceased to perform any works, even the tapas or austerities of the Vânaprastha.