The Vedanta Sutras of Badarayana, Commentary by Sankara (SBE38), tr. by George Thibaut  at sacred-texts.com
32. The works of the âsramas (are incumbent on him) also (who does not desire release); because they are enjoined.
Under Sûtra 26 it has been proved that the work's enjoined on the âsramas are means of knowledge. Now we will consider whether those works have to be performed also by him who does not desire final release and therefore takes his stand on his âsrama merely without wishing for knowledge--Here the pûrvapakshin maintains that as the works incumbent on the âsramas are enjoined as means of knowledge by the passage, 'Him the Brâhmanas seek to know by the study of the Veda' &c., the works of permanent obligation are not to be performed by him who, not desirous of knowledge, wishes for some other fruit. Or else they are to be performed by him also; but then they cannot be means of knowledge, since it would be contradictory to attribute to them a permanent and a non-permanent connexion. 1
Against this conclusion the Sûtrakâra remarks that the works of permanent obligation are to be performed by
him only who, not desirous of release, takes his stand on the âsramas merely, because they are enjoined by texts such 'as long as his life lasts he is to offer the agnihotra.' For to such texts no excessive weight must be ascribed.--The next Sûtra replies to the objection raised above in the words, 'but then they cannot be means of knowledge.'
312:1 I. e. we must not think that because they enjoin the 'nityatâ' of certain works, other passages may not enjoin the same works as mere means of knowledge.