Chapter 2 · The Yoga of Knowledge · Krishna said
Bhagavad Gita 2.16 — Real and unreal
नासतो विद्यते भावो नाभावो विद्यते सतः। उभयोरपि दृष्टोऽन्तस्त्वनयोस्तत्त्वदर्शिभिः ॥
nāsato vidyate bhāvo nābhāvo vidyate sataḥ | ubhayorapi dṛṣṭo'ntastvanayostattvadarśibhiḥ ||
Meaning
The unreal has no lasting existence, and the real never ceases to be. Those who see the truth have understood both.