Mandukya Karika, verse 2.38


तत्त्वमाध्यात्मिकं दृष्ट्वा तत्त्वं दृष्ट्वा तु बाह्यतः ।
तत्त्वीभूतस्तदारामः तत्त्वादप्रच्युतो भवेत् ॥ ३८ ॥

tattvamādhyātmikaṃ dṛṣṭvā tattvaṃ dṛṣṭvā tu bāhyataḥ |
tattvībhūtastadārāmaḥ tattvādapracyuto bhavet || 38 ||

38. Having known the truth regarding what exists internally (i.e., within the body) as well as the truth regarding what exists externally (i.e., the earth, etc.) he becomes one with Reality, derives his pleasure from It and never deviates from the Real.

Shankara Bhashya (commentary)

The truth1 regarding external objects such as the earth, etc., and the truth regarding internal objects characterised by body, etc., is that these are as unreal as a snake seen in the rope, or objects seen in dream or magic. For, there are such Śruti passages as, “modification being only a name, arising from speech, etc.” The Śruti further declares, “Ātman is both within and without, birthless, causeless, having no within or without, entire, all-pervading like the Ākāśa (ether), subtle, unchanging, without attributes and parts, and without action. That is Truth, That is Ātman and That thou art.” Knowing it to be such from the point of view of Truth, he becomes one with Truth and derives his enjoyment2 from Truth and not from any external3 object. But a person4 ignorant of Truth, takes the mind to be the Self and believes the Ātman to be active like the mind, and becomes active. He thus thinks his self to be identified with the body, etc., and deviated from Ātman saying, “Oh, I am now fallen from the Knowledge of Self.” When his mind is concentrated he sometimes thinks that he is happy and one with the Self. He declares “Oh, I am now one with the essence of Truth.” But,5 the knower of Self never makes any such statement, as Ātman is ever one and changeless and as it is impossible for Ātman to deviate from its own nature. The6 consciousness that “I am Brahman” never leaves him. In other words, he never loses the consciousness regarding the essence of the Self. The Smṛti supports this view in such passages as “The wise man views equally a dog or an outcaste.” “He sees who sees the Supreme Lord remaining the same, in all beings.” (Gītā)