The Vedanta Sutras, commentary by Sankaracharya (SBE34), tr. by George Thibaut  at sacred-texts.com
27. But (this is not so), on account of scriptural passages, and on account of (Brahman) resting on Scripture (only).
The word 'but' discards the objection.--We deny this and maintain that our view is not open to any objections.--That the entire Brahman undergoes change, by no means follows from our doctrine, 'on account of sacred texts.' For in the same way as Scripture speaks of the origin of the world from Brahman, it also speaks of Brahman subsisting apart from its effects. This appears from the passages indicating the difference of cause and effect ('That divinity thought) let me enter into these three divinities with this living Self and evolve names and forms;' and, 'Such is the greatness of it, greater than it is the Person; one foot of him are all things, three feet are what is immortal in heaven' (Kh. Up. III, 12, 6); further, from the passages declaring the unmodified Brahman to have its abode in the heart, and from those teaching that (in dreamless sleep) the individual soul is united with the True. For if the entire Brahman had passed into its effects, the limitation (of the soul's union with Brahman) to the state of dreamless sleep which is declared in the passage, 'then it is united with the True, my dear,' would be out of place; since the individual soul is always united with the effects of Brahman, and since an unmodified Brahman does not exist (on that hypothesis). Moreover, the possibility of Brahman becoming the object of perception by means of the senses is denied while its effects may thus be perceived. For these reasons the existence of an unmodified Brahman has to be. admitted.--Nor do we violate those texts which declare Brahman to be without parts; we rather admit Brahman to be without parts just because Scripture reveals it. For Brahman which rests exclusively on the holy texts, and regarding which the holy texts alone are authoritative--
not the senses, and so on--must be accepted such as the texts proclaim it to be. Now those texts declare, on the one hand, that not the entire Brahman passes over into its effects, and, on the other hand, that Brahman is without parts. Even certain ordinary things such as gems, spells, herbs, and the like possess powers which, owing to difference of time, place, occasion, and so on, produce various opposite effects, and nobody unaided by instruction is able to find out by mere reflection the number of these powers, their favouring conditions, their objects, their purposes, &c.; how much more impossible is it to conceive without the aid of Scripture the true nature of Brahman with its powers unfathomable by thought! As the Purâna says: 'Do not apply reasoning to what is unthinkable! The mark of the unthinkable is that it is above all material causes 1.' Therefore the cognition of what is supersensuous is based on the holy texts only.
But--our opponent will say--even the holy texts cannot make us understand what is contradictory. Brahman, you say, which is without parts undergoes a change, but not the entire Brahman. If Brahman is without parts, it does either not change at all or it changes in its entirety. If, on the other hand, it be said that it changes partly and persists partly, a break is effected in its nature, and from that it follows that it consists of parts. It is true that in matters connected with action (as, for instance, in the case of the two Vedic injunctions 'at the atirâtra he is to take the shodasin-cup,' and 'at the atirâtra he is not to take the shodasin-cup') any contradiction which may present itself to the understanding is removed by the optional adoption of one of the two alternatives presented as action is dependent on man; but in the case under discussion the adoption of one of the alternatives does not remove the contradiction because an existent thing (like Brahman) does not (like an action which is to be accomplished) depend on man. We are therefore met here by a real difficulty.
No, we reply, the difficulty is merely an apparent one; as we maintain that the (alleged) break in Brahman's nature is a mere figment of Nescience. By a break of that nature a thing is not really broken up into parts, not any more than the moon is really multiplied by appearing double to a person of defective vision. By that element of plurality which is the fiction of Nescience, which is characterised by name and form, which is evolved as well as non-evolved, which is not to be defined either as the Existing or the Non-existing, Brahman becomes the basis of this entire apparent world with its changes, and so on, while in its true and real nature it at the same time remains unchanged, lifted above the phenomenal universe. And as the distinction of names and forms, the fiction of Nescience, originates entirely from speech only, it does not militate against the fact of Brahman being without parts.--Nor have the scriptural passages which speak of Brahman as undergoing change the purpose of teaching the fact of change; for such instruction would have no fruit. They rather aim at imparting instruction about Brahman's Self as raised above this apparent world; that being an instruction which we know to have a result of its own. For in the scriptural passage beginning 'He can only be described by No, no' (which passage conveys instruction about the absolute Brahman) a result is stated at the end, in the words 'O Ganaka, you have indeed reached fearlessness' (Bri. Up. IV, 2, 4).--Hence our view does not involve any real difficulties.
351:1 Prakritibhya iti, pratyakshadrishtapadârthasvabhâvebhyo yat param vilakshanam âkâryâdyupadesagamyam tad akintyam ity artah Ân. Gi.