The Vedanta Sutras of Badarayana, Commentary by Sankara (SBE38), tr. by George Thibaut  at sacred-texts.com
14. For (Brahman) is merely devoid of form, on account of this being the main purport of scripture.
Brahman, we must definitively assert, is devoid of all form, colour, and so on, and does not in any way possess form, and so on.--Why?--'On account of this being the main purport (of scripture).'--' It is neither coarse nor fine, neither short nor long' (Bri. Up. III, 8, 8); 'That which is without sound, without touch, without form, without decay' (Ka. Up. I, 3, 15); 'He who is called ether is the revealer of all forms and names. That within which forms and names are, that is Brahman' (Kh. Up. VIII, 14, 1); 'That heavenly person is without body, he is both without and within, not produced' (Mu. Up. II, 1, 2); 'That Brahman is without cause and without effect, without anything inside or outside, this Self is Brahman, omnipresent and omniscient' (Bri. Up. II, 5, 19). These and similar passages have for their purport the true nature of Brahman as non-connected with any world, and have not any other purport, as we have proved under I, 1, 4. On the ground of such passages we therefore must definitively conclude that Brahman is devoid of form. Those other passages, on the other hand, which refer to a Brahman qualified by form do not aim at setting forth the nature of Brahman, but rather at enjoining the worship of Brahman. As long as those latter texts do not contradict those of the former class, they are to be accepted as they stand; where, however, contradictions occur, the passages whose main subject is Brahman must be viewed as having greater force than those of the other kind.--This is the reason for our deciding that although there are two different classes of scriptural texts, Brahman must be held to be altogether without form, not
at the same time of an opposite nature.--But what then is the position of those passages which refer to Brahman as possessing form?--To this question the next Sûtra replies.