Madhvaon Brahma Sūtra 3.1.21

“ The Maha Tamas is said to consist of three re- gions ; the topmost, the middle, the nethermost. Since mere hearing of the nethermost region described would bring on swoon, etc., O best of kings, it is not described to you at length,” (Kurmapurana). “Having become smoke, he becomes cloud,” etc. (Ch. V. 10.5). In these Srutis, the soul, it seems, is said to become transformed into other things (i.e., is said to attain to the state of being another). The question arises how it can be. In answer, the Sutrakara says: