The Vedanta Sutras of Badarayana, Commentary by Sankara (SBE38), tr. by George Thibaut  at sacred-texts.com
REVERENCE TO THE HIGHEST SELF!
1. In the intermediate place there is (a real) creation; for (scripture) says (that).
In the preceding pâda we have set forth, with reference to the knowledge of the five fires, the various stages of the soul's passing through the samsâra. We shall now set forth the soul's different states (waking, dreaming, &c.)--Scripture says (Bri. Up. IV, 3, 9; 10), 'When he falls asleep--; there are no chariots in that state, no horses, no roads, but he himself creates chariots, horses, and roads,' &c.--Here a doubt arises whether the creation thus taking place in dreams is a real one (pâramârthika) like the creation seen in the waking state, or whether it consists of illusion (mâyâ).--The pûrvapakshin maintains that 'in the intermediate place (or state) there is (a real) creation.' By intermediate place we have to understand the place of dreams, in which latter sense the word is used in the Veda, 'There is a third intermediate state, the state of dreams' (Bri. Up. IV, 3, 9). That place is called the intermediate place because it lies there where the two worlds, or else the place of waking and the place of bliss (deep sleep), join. In that intermediate place the creation must be real; because scripture, which is authoritative, declares it to be so, 'He creates chariots, horses, roads,' &c. We, moreover, infer this from the concluding clause, 'He indeed is the maker' (Bri. Up. IV, 3, 10).