The Vedanta Sutras, commentary by Sankaracharya (SBE34), tr. by George Thibaut  at sacred-texts.com
33. Bâdarâyana, on the other hand, (maintains) the existence (of qualification for Brahma-vidyâ on the part of the gods); for there are (passages indicatory of that).
The expression 'on the other hand' is meant to rebut the pûrvapaksha. The teacher, Bâdarâyana, maintains the existence of the qualification on the part of the gods, &c. For, although the qualification of the gods cannot be admitted with reference to the madhu-vidyâ, and similar topics of knowledge, in which the gods themselves are implicated, still they may be qualified for the pure knowledge of Brahman, qualification in general depending on the presence of desire, capability, &c. 2 Nor does the impossibility of qualification in certain cases interfere with the presence of qualification in those other cases where it is not impossible. To the case of the gods the same reasoning applies as to the case of men; for among men also, all are not qualified for everything, Brâhmanas, for instance, not for the râgasûya-sacrifice 3.
[paragraph continues] And, with reference to the knowledge of Brahman, Scripture, moreover, contains express hints notifying that the devas are qualified; compare, for instance, Bri. Up. 1, 4, 10, 'Whatever Deva was awakened (so as to know Brahman) he indeed became that; and the same with rishis;' Kh. Up. VIII, 7, 2, 'They said: Well, let us search for that Self by which, if one has searched it out, all worlds and all desires are obtained. Thus saying, Indra went forth from the Devas, Virokana from the Asuras.' Similar statements are met with in Smriti, so, for instance, in the colloquy of the Gandharva and Yâgñavalkya 1.--Against the objection raised in the preceding Sûtra (32) we argue as follows. Words like âditya, and so on, which denote devas, although having reference to light and the like, yet convey the idea of certain divine Selfs (persons) endowed with intelligence and pre-eminent power; for they are used in that sense in mantras and arthavâda passages. For the devas possess, in consequence of their pre-eminent power, the capability of residing within the light, and so on, and to assume any form they like. Thus we read in Scripture, in the arthavâda passage explaining the words 'ram of Medhâtithi,' which form part of the Subrahmanya-formula, that 'Indra, having assumed the shape of a ram, carried off Medhâtithi, the descendant of Kanva' (Shadv. Br. I, 1). And thus Smriti says that 'Âditya, having assumed the shape of a man, came to Kuntî.' Moreover, even in such substances as earth, intelligent ruling beings must be admitted to reside, for that appears from such scriptural passages as 'the earth spoke,' 'the waters spoke,' &c. The non-intelligence of light and the like, in so far as they are mere material elements, is admitted in the case of the sun (âditya), &c. also; but--as already remarked--from the use of the words in mantras and
arthavâdas it appears that there are intelligent beings of divine nature (which animate those material elements).
We now turn to the objection (raised above by the pûrvapakshin) that mantras and arthavâdas, as merely subserving other purposes, have no power of setting forth the personality of the devas, and remark that not the circumstance of subordination or non-subordination to some other purpose, but rather the presence or absence of a certain idea furnishes a reason for (our assuming) the existence of something. This is exemplified by the case of a person who, having set out for some other purpose, (nevertheless) forms the conviction of the existence of leaves, grass, and the like, which he sees lying on the road.--But, the pûrvapakshin may here object, the instance quoted by you is not strictly analogous. In the case of the wanderer, perception, whose objects the grass and leaves are, is active, and through it he forms the conception of their existence. In the case of an arthavâda, on the other hand, which, as forming a syntactical unity with the corresponding injunctory passage, merely subserves the purpose of glorifying (the latter), it is impossible to determine any energy having a special object of its own. For in general any minor syntactical unity, which is included in a more comprehensive syntactical unity conveying a certain meaning, does not possess the power of expressing a separate meaning of its own. Thus, for instance, we derive, from the combination of the three words constituting the negative sentence, '(Do) not drink wine,' one meaning only, i.e. a prohibition of drinking wine, and do not derive an additional meaning, viz. an order to drink wine, from the combination of the last two words, 'drink wine.'--To this objection we reply, that the instance last quoted is not analogous (to the matter under discussion). The words of the sentence prohibiting the drinking of wine form only one whole, and on that account the separate sense which any minor syntactical unity included in the bigger sentence may possess cannot be accepted. In the case of injunction and arthavâda, on the other hand, the words constituting the arthavâda form a separate group of their own which refers to some accomplished
thing 1, and only subsequently to that, when it comes to be considered what purpose they subserve, they enter on the function of glorifying the injunction. Let us examine, as an illustrative example, the injunctive passage, 'He who is desirous of prosperity is to offer to Vâyu a white animal.' All the words contained in this passage are directly connected with the injunction. This is, however, not the case with the words constituting the corresponding arthavâda passage, 'For Vâyu is the swiftest deity; Vâyu he approaches with his own share; he leads him to prosperity.' The single words of this arthavâda are not grammatically connected with the single words of the injunction, but form a subordinate unity of their own, which contains the praise of Vâyu, and glorify the injunction, only in so far as they give us to understand that the action enjoined is connected with a distinguished divinity. If the matter conveyed by the subordinate (arthavâda) passage can be known by some other means of knowledge, the arthavâda acts as a mere anuvâda, i.e. a statement referring to something (already known) 2. When its contents are contradicted by other means of knowledge it acts as a so-called gunavâda, i.e. a statement of a quality 3. Where, again, neither of the two mentioned conditions is found, a doubt may arise whether the arthavâda is to be taken as a gunavâda on account of the absence of other means of knowledge, or as an arthavâda referring to something known (i.e. an anuvâda) on account of the absence of contradiction by other means of proof. The latter alternative is, however, to be embraced by reflecting people.--The same reasoning applies to mantras also.
There is a further reason for assuming the personality of the gods. The Vedic injunctions, as enjoining sacrificial offerings to Indra and the other gods, presuppose certain characteristic shapes of the individual divinities, because
without such the sacrificer could not represent Indra and the other gods to his mind. And if the divinity were not represented to the mind it would not be possible to make an offering to it. So Scripture also says, 'Of that divinity for which the offering is taken he is to think when about to say vaushat' (Ai. Br. III, 8, 1). Nor is it possible to consider the essential form (or character) of a thing to consist in the word only 1; for word (denoting) and thing (denoted) are different. He therefore who admits the authoritativeness of the scriptural word has no right to deny that the shape of Indra, and the other gods, is such as we understand it to be from the mantras and arthavâdas.--Moreover, itihâsas and purânas also--because based on mantra and arthavâda which possess authoritative power in the manner described--are capable of setting forth the personality, &c. of the devas. Itihâsa and purâna can, besides, be considered as based on perception also. For what is not accessible to our perception may have been within the sphere of perception of people in ancient times. Smriti also declares that Vyâsa and others conversed with the gods face to face. A person maintaining that the people of ancient times were no more able to converse with the gods than people are at present, would thereby deny the (incontestable) variety of the world. He might as well maintain that because there is at present no prince ruling over the whole earth, there were no such princes in former times; a position by which the scriptural injunction of the râgasûya-sacrifice 2would be stultified. Or he might maintain that in former times the spheres of duty of the different castes and âsramas were as generally unsettled as they are now, and, on that account, declare those parts of Scripture which define those different duties to be purposeless. It is therefore altogether unobjectionable to assume that the men of ancient times, in consequence of their eminent religious
merit, conversed with the gods face to face. Smriti also declares that 'from the reading of the Veda there results intercourse with the favourite divinity' (Yoga Sûtra II, 44). And that Yoga does, as Smriti declares, lead to the acquirement of extraordinary powers, such as subtlety of body, and so on, is a fact which cannot be set aside by a mere arbitrary denial. Scripture also proclaims the greatness of Yoga, 'When, as earth, water, light, heat, and ether arise, the fivefold quality of Yoga takes place, then there is no longer illness, old age, or pain for him who has obtained a body produced by the fire of Yoga' (Svet. Up. II, 12). Nor have we the right to measure by our capabilities the capability of the rishis who see the mantras and brâhmana passages (i.e. the Veda).--From all this it appears that the itihâsas and purânas have an adequate basis.--And the conceptions of ordinary life also must not be declared to be unfounded, if it is at all possible to accept them.
The general result is that we have the right to conceive the gods as possessing personal existence, on the ground of mantras, arthavâdas, itihâsas, purânas, and ordinarily prevailing ideas. And as the gods may thus be in the condition of having desires and so on, they must be considered as qualified for the knowledge of Brahman. Moreover, the declarations which Scripture makes concerning gradual emancipation 1agree with this latter supposition only.
218:2 See above, p. 197.
218:3 Which can be offered by kshattriyas only.
219:1 Srautalingenânumânabâdham darsayitvâ smârtenâpi tadbâdham darsayati smârtam iti. Kim atra brahma amritam kim svid vedyam anuttamam, kintayet tatra vai gatvâ gandharvo mâm aprikkhata, Visvâvasus tato râgan vedântagñânakovida iti mokshadharme ganakayâgñavalkyasamvâdât prahlâdâgagarasamvâdâk koktânumânâsiddhir ity arthah.
221:1 As opposed to an action to be accomplished.
221:2 Of this nature is, for instance, the arthavâda, 'Fire is a remedy for cold.'
221:3 Of this nature is, for instance, the passage 'the sacrificial post is the sun' (i.e. possesses the qualities of the sun, luminousness, &c.; a statement contradicted by perception).
222:1 And therefore to suppose that a divinity is nothing but a certain word forming part of a mantra.
222:2 The râgasûya-sacrifice is to be offered by a prince who wishes to become the ruler of the whole earth.
223:1 In one of whose stages the being desirous of final emancipation becomes a deva.