The Vedanta Sutras, commentary by Sankaracharya (SBE34), tr. by George Thibaut  at sacred-texts.com
26. Also (beings) above them, (viz. men) (are qualified for the study and practice of the Veda), on account of the possibility (of it), according to Bâdarâyana.
It has been said above that the passage about him who is of the size of a thumb has reference to the human heart, because men are entitled to study and act according to the sâstra. This gives us an occasion for the following discussion.--It is true that the sâstra entitles men, but, at the same time, there is no exclusive rule entitling men only to the knowledge of Brahman; the teacher, Bâdarâyana, rather thinks that the sâstra entitles those (classes of beings) also which are above men, viz. gods, and so on.--On what account?--On the account of possibility.--For in their cases also the different causes on which the qualification depends, such as having certain desires, and so on, may exist. In the first place, the gods also may have the desire of final release, caused by the reflection that all effects, objects, and powers are non-permanent. In the second place, they may be capable of it as their corporeality appears from mantras, arthavâdas, itihâsas, purânas, and ordinary experience. In the third place, there is no prohibition (excluding them like Sûdras). Nor does, in the fourth place, the scriptural rule about the upanayana-ceremony annul their title; for that
ceremony merely subserves the study of the Veda, and to the gods the Veda is manifest of itself (without study). That the gods, moreover, for the purpose of acquiring knowledge, undergo discipleship, and the like, appears from such scriptural passages as 'One hundred and one years Indra lived as a disciple with Pragâpati' (Kh. Up. VIII, ii, 3), and 'Bhrigu Vâruni went to his father Varuna, saying, "Sir, teach me Brahman"' (Taitt. Up. III, 1).--And the reasons which have been given above against gods and rishis being entitled to perform religious works (such as sacrifices), viz. the circumstance of there being no other gods (to whom the gods could offer sacrifices), and of there being no other rishis (who could be invoked during the sacrifice), do not apply to the case of branches of knowledge. For Indra and the other gods, when applying themselves to knowledge, have no acts to perform with a view to Indra, and so on; nor have Bhrigu and other rishis, in the same case, to do anything with the circumstance of their belonging to the same gotra as Bhrigu, &c. What, then, should stand in the way of the gods' and rishis' right to acquire knowledge?--Moreover, the passage about that which is of the size of a thumb remains equally valid, if the right of the gods, &c. is admitted; it has then only to be explained in each particular case by a reference to the particular size of the thumb (of the class of beings spoken of).