The System of the Vedanta according to Badarayana's Brahma-Sutras and Cankara's Commentary c7.s3.t3.2

c7.s3.t3.2

As Âkâça came forth from Âtman, so Vâyu (air or wind) came forth from Âkâça; its immortality and imperishability, as taught by the scripture (Chând. 4, 3, 1. Brih. 1, 5, 22) are to be taken as only relative (âpekshika), that is, in comparison with the other elements, which all come forth from, and return to it, and only hold good in the lower doctrine (p. 626, 5), which seems to mean that, in the passage in question (Brih. 1, 5, 22), Vâyu is the representative of aparam brahma. As from Âkâça proceeds air, so from this proceeds fire (2, 3, 10), from fire water (2, 3, 11), and from water, earth (2, 3, 12), for this, and not rice or barley, is to be understood by "food" in the passage of the Chândogya at the beginning of this chapter, firstly, because the context requires this, and this is of more importance than the use of words (p. 634, 5) and also because "the food" is spoken of further on (Chând. 6, 4) as "black" and this refers to the earth which in some parts, it is true, is white like milk, and red, like [glowing] coals, (p. 633, 9), but as a rule is black, for which reason it is also called Çarvarî (night) in the Purāṇas (p. 633, 11). Plants, according to other passages, spring from the earth later and therefore the word "food" refers to the earth.