Mandukya Karika, verse 2.29


यं भावं दर्शयेद्यस्य तं भावं स तु पश्यति ।
तं चावति स भूत्वासौ तद्ग्रहः समुपैति तम् ॥ २९ ॥

yaṃ bhāvaṃ darśayedyasya taṃ bhāvaṃ sa tu paśyati |
taṃ cāvati sa bhūtvāsau tadgrahaḥ samupaiti tam || 29 ||

29. He (the inquirer) cognizes only that idea that is presented to him. It (Ātman) assumes the form (of what is cognized) and thus protects (the inquirer). Possessed by that (idea) he realises it (as the sole essence).

Shankara Bhashya (commentary)

What more is to be gained (by this kind of endless discussion)? Whatever idea or interpretation of such things as Prāṇa, 1 etc., narrated above or omitted, is shown to the inquirer by the teacher or other trustworthy person. He realises2 that as the sole essence (Ātman), i.e., he understands that as “I am that or that is mine”. Such conception about Ātman as is revealed to the inquirer, appears to him as the sole essence and protects him, i.e., keeps him away from all other ideas (because it appears to him as the highest ideal). On3 account of his devotion (attachment) to that ideal, he realises it as the sole essence in due course, i.e., attains his identity with it. 1 Prāṇa—All interpretations of Ātman must be included in the Prāṇa, as Prāṇa or the causal Self is the highest manifestation of Ātman in the relative plane. 2 Realises, etc.—It is because such inquirer, for want of proper discrimination, accepts the words of the teacher as the highest truth. The teacher also, realising the limited intellectual capacity of the student, teaches him, at first, only a partial view of truth. 3 On account, etc.—Such student only gets a partial view of Reality though he takes it as the sole essence. He shuts his eyes to other views. On account of his single-minded devotion to that ideal he becomes intolerent of other view-points. But he who takes a particular idea to be the Reality and condemns other ideas as untrue, has not realised the Highest Truth. For, to a knower of Reality, all imaginations are identical with Brahman and hence have the same value. This is the mistake generally committed by the mystics who, for want of the faculty of rational discrimination, do not see any truth in the views of others.