Vasiṣṭha's teaching (Mahārāmāyaṇa) 6.28.p16

6.28.p16

15. [Sanskrit available] The belief of the existence of body makes it a reality, the unreal seems as real, and therefore it is said to be both real and unreal at the same time. (The perception is real but the object of perception an unreality. Just so the perception of a snake in the rope may be true, though the snake in the rope is quite untrue).