The Vedanta Sutras, commentary by Sankaracharya (SBE34), tr. by George Thibaut  at sacred-texts.com
32. And (the devas, &c. are not qualified) on account of (the words denoting the devas, &c.) being (used) in the sense of (sphere of) light.
To that sphere of light, the pûrvapakshin resumes, which is stationed in the sky, and during its diurnal revolutions illumines the world, terms such as Âditya, i.e. the names of devas, are applied, as we know from the use of ordinary language, and from Vedic complementary passages 1. But of a mere sphere of light we cannot understand how it should be endowed with either a bodily form, consisting of the heart and the like, or intelligence, or the capability of forming wishes 2. For mere light we know to be, like earth, entirely devoid of intelligence. The same observation applies to Agni (fire), and so on. It will perhaps be said that our objection is not valid, because the personality of the devas is known from the mantras, arthavâdas, itihâsas, purânas, and from the conceptions of ordinary life 3; but we contest the relevancy of this remark. For the conceptions of ordinary life do not constitute an independent means of knowledge; we rather say that a thing is known from ordinary life if it is known by the (acknowledged) means of knowledge, perception, &c. But none of the recognised means of knowledge, such as perception and the like, apply to the
matter under discussion. Itihâsas and purânas again being of human origin, stand themselves in need of other means of knowledge on which to base. The arthavâda passages also, which, as forming syntactical wholes with the injunctory passages, have merely the purpose of glorifying (what is enjoined in the latter), cannot be considered to constitute by themselves reasons for the existence of the personality, &c. of the devas. The mantras again, which, on the ground of direct enunciation, &c., are to be employed (at the different stages of the sacrificial action), have merely the purpose of denoting things connected with the sacrificial performance, and do not constitute an independent means of authoritative knowledge for anything 1.--For these reasons the devas, and similar beings, are not qualified for the knowledge of Brahman.
217:1 As, for instance, 'So long as Âditya rises in the east and sets in the west' (Kh. Up. III, 6, 4).
217:2 Whence it follows that the devas are not personal beings, and therefore not qualified for the knowledge of Brahman.
217:3 Yama, for instance, being ordinarily represented as a person with a staff in his hand, Varuna with a noose, Indra with a thunderbolt, &c. &c.
218:1 On the proper function of arthavâda and mantra according to the Mîmâmsâ, cp. Arthasamgraha, Introduction.