SB 10.85.12

naśvareṣv iha bhāveṣu
 tad asi tvam anaśvaram
yathā dravya-vikāreṣu
 dravya-mātraṁ nirūpitam
Word for word: 
naśvareṣu — subject to destruction; iha — in this world; bhāveṣu — among entities; tat — that; asi — are; tvam — You; anaśvaram — the indestructible; yathā — just as; dravya — of a substance; vikāreṣu — among the transformations; dravya-mātram — the substance itself; nirūpitam — ascertained.
Translation: 
You are the one indestructible entity among all the destructible things of this world, like the underlying substance that is seen to remain unchanged while the things made from it undergo transformations.