Bhagavad Gita 2.27

For death is certain for that which is born, just as birth is certain for that which is dead. Therefore, do not grieve for what is inevitable.

जातस्य हि ध्रुवो मृत्युर्ध्रुवं जन्म मृतस्य च।
तस्मादपरिहार्येऽर्थे न त्वं शोचितुमर्हसि॥

jātasya hi dhruvo mṛtyurdhruvaṃ janma mṛtasya ca|
tasmādaparihārye'rthe na tvaṃ śocitumarhasi||

English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).