Mandukya Karika, verse 2.33


भावैरसद्भिरेवायमद्वयेन च कल्पितः ।
भावा अप्यद्वयेनैव तस्मादद्वयता शिवा ॥ ३३ ॥

bhāvairasadbhirevāyamadvayena ca kalpitaḥ |
bhāvā apyadvayenaiva tasmādadvayatā śivā || 33 ||

33. This (the Ātman) is imagined both as unreal objects that are perceived and as the non-duality. The objects (Bhāvas) are imagined in the non-duality itself. Therefore, non-duality (alone) is the (highest) bliss.

Shankara Bhashya (commentary)

The reason for the interpretation of the previous verse is thus stated: Just as in a rope, an unreal snake, streak of water or the like is imagined, which are nonseparate (non-dual) from the existing rope,—the same (rope) being spoken of as this snake, this streak of water, this stick, or the like,—even so this Ātman is imagined to be the innumerable objects such as Prāṇa, etc., which are unreal1 and perceived only through ignorance, but not from the standpoint of the Ultimate Reality. For,2 unless the mind is active, nobody is ever able to perceive any object. But no action is possible for Ātman. Therefore the objects that are perceived to exist by the active mind can never be imagined to have existence from the standpoint of the Ultimate Reality. It is therefore this (non-dual) Ātman which alone is imagined as such illusory objects as Prāṇa, etc., which are perceived, as well as the3 non-dual and ultimately real Ātman (which is the substratum of illusory ideas, such as Prāṇa, etc.) in the same manner as the rope is imagined as the substratum of the illusion of the snake. Though4 always one and unique (i.e., of the nature of the Ātman), the Prāṇa, etc., the entities that are perceived, are imagined (from the standpoint of ignorance) as having the nondual and ultimately real Ātman as their substratum. For, no illusion is ever perceived without a substratum. As “non-duality” is the substratum of all illusions (from the standpoint of ignorance) and also as it is, in its real nature, ever unchangeable, non-duality alone is (the highest) bliss even5 in the state of imagination, i.e., the empirical experiences. Imaginations alone (which make Prāṇa, etc., appear as separate from Ātman) are the cause of misery.6 These imaginations cause fear, etc., like the imaginations of the snake, etc., in the rope. Non-duality7 is free from fear and therefore it is the (highest) bliss.