Bhagavad Gita · 2.11

श्रीभगवानुवाचअशोच्यानन्वशोचस्त्वं प्रज्ञावादांश्च भाषसे।गतासूनगतासूंश्च नानुशोचन्ति पण्डिताः॥

śhrī bhagavān uvācha aśhochyān anvaśhochas tvaṁ prajñā-vādāṁśh cha bhāṣhase gatāsūn agatāsūṁśh cha nānuśhochanti paṇḍitāḥ

The Supreme Lord said: You grieve for those who should not be grieved for, yet you speak words of wisdom. The wise grieve neither for the living nor for the dead.

— Bhagavad Gita 2.11

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)