Bhagavad Gita: Chapter 2, Verse 11

श्री भगवानुवाच
अशोच्यनन्वशोचस्त्वं प्रज्ञावादांश्च भाषसे ।
गतासूनगतासूंश्च नानुशोचन्ति पण्डिताः ॥ २-११ ॥

śrī-bhagavān uvāca
aśocyān anvaśocas tvaṁ prajñā-vādāṁś ca bhāṣase
gatāsūn agatāsūṁś ca nānuśocanti paṇḍitāḥ 2.11

Sri Krishna Bhagawan said: While you speak learned words, you are mourning for what is not worthy of grief. The wise lament neither for the living nor for the dead.