The System of the Vedanta according to Badarayana's Brahma-Sutras and Cankara's Commentary c7.s3.t7.12

c7.s3.t7.12

“But if no external object exists, whence comes the variety of perceptions?—We answer: from the variety of (subjective) phenomena (*vāsanā*). Because in the beginningless Samsāra, the presentations and the phenomena, like seed and plant, are in turn the cause and effect of each other, variety is explained without contradiction. Also it is to be understood that, for the rule (waking), as well as for the exception (sleep), variety of knowledge has its ground solely in phenomena. And we both agree that in dream, etc., without any outward things, a variety of knowledge is produced by phenomena; only that I admit no variety of knowledge caused by external objects and not by phenomena. And therefore again there are no external objects.”