Brahma Sutras – According to Shankara 3-3-28
Topic 28 - Meditations on Vāyu and Prāṇa are to be kept separate in spite of the essential oneness of these two
प्रदानवदेव, तदुक्तम् ॥ ४३ ॥
pradānavadeva, taduktam uktam || 43 ||
pradānavat—As in the case of the offerings; eva—exactly; tat–that; uktam—has been stated.
43. (The meditations on Vāyu and Prāṇa are different owing to their different functions, though the two are essentially one); (it is) exactly as in the case of the offerings (of cakes to Indra the ruler, the monarch, and the sovereign separately). This has been stated (by Jaimini in Pūrva Mīmāṃsā-Sutras).
In the Samvarga Vidyā of the Chāṇḍogya, meditation on Prāṇa with reference to the body and on Vāyu with reference to the gods is prescribed.
Now many texts declare that Prāṇa and Vāyu are one in essence. So the opponent holds that the two meditations can be combined.
The Sutra refutes the view and says that they are to be kept apart, in spite of the non-difference in nature of Vāyu and Prāṇa; for their functions due to their different abodes are different.
Just as oblations are separately given to Indra the ruler, the monarch, and the sovereign according to his different capacities, though he is one god; so the meditations on Vāyu and Prāṇa have to be kept apart.
This principle is established by Jaimini in Pūrva Mīmāṃsā.