The Vedanta Sutras of Badarayana, Commentary by Sankara (SBE38), tr. by George Thibaut  at sacred-texts.com
2. From the year to Vâyu; on account of the absence and presence of specification.
But by what special combination can we establish between
the different attributes of the road the relation of what is determined by attributes and of determining attributes? The teacher out of kindness to us connects them as follows.--The Kaushîtakins describe the road of the gods as follows, 'Having reached the path of the gods he comes to the world of Agni, to the world of Vâyu, to the world of Varuna, to the world of Indra, to the world of Pragâpati, to the world of Brahman' (Kau. Up. I, 3). Now the world of Agni means the same as light, since both terms denote burning, and we therefore need not, with regard to them, search for the order in which they are to be combined. Vâyu, on the other hand, is not mentioned in the road beginning with light; in what place then is he to be inserted?--We read, Kh. Up. V, 10, 1, 'They go to the light, from light to day, from day to the waxing half of the moon, from the waxing half of the moon to the six months when the sun goes to the north, from those months to the year, from the year to Âditya.' Here they reach Vâyu after the year and before Âditya.--Why so?--'On account of the absence and presence of specification.' About Vâyu--concerning whom the passage, 'He goes to the world of Vâyu,' contains no specification--another passage does state such a specification, viz. Bri. Up. V, 10, 1, 'When the person goes away from this world he comes to Vâyu. Then Vâyu makes room for him like the hole of a wheel. and through it he mounts higher, he comes to Âditya.' On account of this specification which shows Vâyu to come before Âditya, Vâyu must be inserted between the year and Âditya.--But as there is a specification showing that Vâyu comes after Agni, why is he not inserted after the light?--There is no such specification, we reply.--But a scriptural passage has been quoted which runs as follows, 'Having reached the path of the gods he comes to the world of Agni, to the world of Vâyu.'--In that passage, we reply, we have only two clauses, of which the text exhibits one before the other, but there is no word expressing order of succession. We have there only a simple statement of facts, 'He goes to this and to that.' But in the other text we perceive a regular order of succession;
for it intimates that after having mounted on high through an opening as large as the wheel of a chariot, granted by Vâyu, he approaches the sun. The Sûtra therefore rightly says, 'On account of the absence and presence of specification.'--The Vâgasaneyins in their text record that he proceeds 'from the months to the world of the gods, from the world of the gods to the sun' (Bri. Up. VI, 2, 15). Here, in order to maintain the immediate succession of Vâyu and Âditya, we must suppose the souls to go from the world of the gods to Vâyu. What the Sûtra says about the soul going to Vâyu from the year has reference to the text of the Khândogya. As between the Vâgasaneyaka and the Khândogya, the world of the gods is absent from one, the year from the other. As both texts are authoritative, both stages have to be inserted in each, and the distinction has to be made that, owing to its connexion with the months, the year has the first place (i.e. after the months and before the world of the gods), and the world of the gods the second place.