Śaṅkaraon Brahma Sūtra 3.4.33

Those works are also co-operative with knowledge just because they are enjoined as such, viz. in passages such as ‘ Him the Brahma;/as seek to know by the study of the Veda,’ &c. This has been explained under Sutra 26. Nor must you think that the texts stating the co-operation of the works of the ajranias towards knowledge refer to the fruit of knowledge, as e. g. the offerings called prayd^as co-operate towards the fruit of the dar^apur/^ani^sa of which they are auxiliary members; for knowledge is not characterised by injunction, and the fruit of knowledge is not to be effected by means. Means characterised by injunctions such as the dar^apiir/zamasa-sacrifice which aim at bringing about certain fruits such as the heavenly world require other (subordinate) means co-operating towards the fruit (such as the praya^s). But not so knowledge. Compare on this point Sutra 25. Therefore texts stating the co-operation of works (with knowledge) have to be interpreted as stating that works are means for the origination of knowledge.—Nor need we fear that thus there arises a contradiction of permanent and non-permanent connexion. For there may be difference of connexion even where there is no difference of work. One connexion is permanent, resting on the texts about the life-long performance of the agnihotra and so on ; of this knowledge is not the result. The other connexion is non-permanent, resting on texts such as ‘ Him the Brahmawas seek to know,’ &c. ; of this knowledge is the result. The case is analogous to that of the one khadira, which through a permanent connexion serves the purpose of the sacrifice, and through a non-permanent connexion the purpose of man.