The Grihya Sutras, Part 1 (SBE29), by Hermann Oldenberg, , at sacred-texts.com
1 1. After one year (the teacher) recites the Sâvitrî (to the student),
2. (Or) after three nights,
3. Or immediately.
4 4-6. Let him recite a Gâyatrî to a Brâhmana,
5. A Trishtubh to a Kshatriya,
6. A Gagatî to a Vaisya.
7. But let it be anyhow a verse sacred to Savitar.
8. They seat themselves to the north of the fire,
9 9. The teacher with his face turned eastward, the other westward.
10 10-11. After (the student) has said, 'Recite, sir!'
11. The teacher, having pronounced the word OM, then causes the other one to say, 'Recite the Sâvitrî, sir!'
12. He then recites the Sâvitrî to him, the verse 'That glorious (splendour) of Savitar' (Rig-Veda III, 62, 10); (firstly) pâda by pâda, (then) hemistich by hemistich, (and finally) without a stop.
66:1 5, 1. The study of the Veda is opened by the Sâvitrî. Comp. Satapatha Brâhmana, loc. cit., §§ 6 seq.
66:4-6 The Gâyatrî which the teacher shall recite to a Brâhmana is the same verse of which it is said below, chap. q, II, that it belongs to Visvâmitra (Rig-veda III, 62, to); the Trishtubh which is taught to the Kshatriya is a verse ascribed to Hiranyastûpa, Rig-veda I, 35, 2; the Gagatî which is to be repeated to a Vaisya is Rig-veda IV, 40, 5, belonging to Vâmadeva, or Rig-veda I, 35, 9, belonging to Hiranyastûpa. See the note on chap. 7, 10.
66:9 The same position is prescribed, in the same words, for the study of the main part of the Veda, below, chap. 7, 3; during p. 67 the study of the Âranyaka the position is slightly different (VI, 3, 2). According to Nârâyana this Sûtra would contain a nishedha of the Sûtras 828 and 829 of the Rig-veda-Prâtisâkhya (p. ccxcii of Professor Max Müller's edition).
67:10-11 10, 11. The Indian tradition divides these Sûtras after âkâryah, so that the words adhîhi bho would have to be pronounced by the teacher. Thus also Nârâyana explains, âkârya adhîhi bho 3 iti mânavakam uktvâ, &c. In my opinion it is the student or the students who say adhîhi bho. Thus the Prâtisâkhya (Sûtra 831, ed. Max Müller) says, 'They invite him with the words adhîhi bho 3, all the students the teacher, having embraced his feet.' Comp. also below, IV, 8, 12, the greater part of which Sûtra is word for word identical with these rules; VI, 3, 6; Gautama I, 46; Gobhila II, 10, 38.