Bhagwad Gita
Chapter 2, Verse 28
अव्यक्तादीनि भूतानि व्यक्तमध्यानि भारत।
अव्यक्तनिधनान्येव तत्र का परिदेवना।।2.28।।
All created beings are unmanifest in their beginning, manifest in their interim state, and unmanifest again when they are annihilated. So what need is there for lamentation?