The Upanishads, Part 1 (SBE01), by Max Müller, , at sacred-texts.com
1. Thus he reached the house of his teacher. The teacher said to him: 'Satyakâma.' He replied: 'Sir.'
2. The teacher said: 'Friend, you shine like one who knows Brahman. Who then has taught you 1?' He replied: 'Not men. But you only, Sir, I wish, should teach me 2;
3. 'For I have heard from men like you, Sir, that only knowledge which is learnt from a teacher (Âkârya), leads to real good.' Then he taught him the same knowledge. Nothing was left out, Yea, nothing was left out.
64:1 It would have been a great offence if Satyakâma had accepted instruction from any man, except his recognised teacher.
64:2 The text should be, bhagavâms tv eva me kâme brûyât (me kâme = mamekkhâyâm).