Bhagavad Gita Chapter 08, Text 20

Bg 8.20

paras tasmat tu bhavo ’nyo
’vyakto ’vyaktat sanatanah
yah sa sarvesu bhutesu
nasyatsu na vinasyati

Word for word: 
parah — transcendental; tasmat — to that; tu — but; bhavah — nature; anyah — another; avyaktah — unmanifest; avyaktat — to the unmanifest; sanatanah — eternal; yah sah — that which; sarvesu — all; bhutesu — manifestation; nasyatsu — being annihilated; na — never; vinasyati — is annihilated.

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Yet there is another unmanifest nature, which is eternal and is transcendental to this manifested and unmanifested matter. It is supreme and is never annihilated. When all in this world is annihilated, that part remains as it is.

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Krishna’s superior, spiritual energy is transcendental and eternal. It is beyond all the changes of material nature, which is manifest and annihilated during the days and nights of Brahma. Krishna’s superior energy is completely opposite in quality to material nature. Superior and inferior nature are explained in the Seventh Chapter.