1. He who having initiated a youth and instructed him in the Vratas, teaches him (one branch of) the Veda (together with its Angas, such as that relating to phonetics, and the rest) is called Âkârya (teacher).
[51.  Taitt. Ârany. I, 30.
XXIX. 1. Âpast. I, 1, 1, 13; Gaut., I, 9.--13. M. II. 140-143; Y. I, 34, 35.--7-10. M. II, 111, 112, 114, 115.--9, 10. See Bühler, Introd. to Digest, p. xxix.
1. The Vratas of a student are certain observances to be kept by him before he is admitted to the regular course of study of the Veda, and again before he is allowed to proceed to the study of the Mahânâmnî verses and to the other higher stages of Vedic learning. See, particularly, Sânkh. II, 11, 12, with Dr. Oldenberg's note (Ind. Stud. XV, 139).]
2. He who teaches him (after he has been initiated by another) either (an entire branch of the Veda) in consideration of a fee, or part of a Veda (without taking a fee), is called Upâdhyâya (sub-teacher).
3. He who performs sacrifices (whether based upon Sruti or upon Smriti) is called Ritvig (officiating priest).
4. He must not engage a priest for the performance of sacrifices without having ascertained (his descent, character, and conduct).
5. Neither must he admit to his teaching (one whom he does not know).
6. And he must not initiate such a one.
7. If one answers improperly, or the other asks improperly, that one (or both) will perish or incur hatred.
8. If by instructing a pupil neither religious merit nor wealth are acquired, and if no sufficient attention is to be obtained from him (for his teacher's words), in such soil divine knowledge must not be sown: it would perish like fine seed in barren soil.
9. The deity of sacred knowledge approached a Brâhmana (and said to him), 'Preserve me, I am thy treasure, reveal me not to a scorner, nor to a wicked man, nor to one of uncontrolled passions: thus I shall be strong
10. 'Reveal me to him, as to a keeper of thy gem, O Brâhmana, whom thou shalt know to be pure, attentive, possessed of a good memory, and chaste, who will not grieve thee, nor revile thee.'
[7. 1 A proper question is, e. g. if the pupil modestly says, 'I don't know about this, therefore I want to be instructed.' An improper question is, e.g. if he says, 'Why do you pronounce this thus wrongly?' An improper answer is an answer to an improper question. (Nand.)]