Madhvaon Brahma Sūtra 3.4.35
Dvaita Vedānta
Sūtra
अनभिभवञ्च दर्शयति
anabhibhavañca darśayati
Sūtra translation
(Scripture) shows also the immutability (of their nature).
The following Sruti shows the unchangeableness of (essential) nature thus : “ The gods attain to (develop), the divine nature and Asuras to the A'sura (evil) nature; and of these two there is never a change in respect of their essential character; for nature does only continue to stand (assert itself).