Chapter 2 · verse 25 · gita.yoga.org

Bhagavad Gita 2.25

अव्यक्तोऽयमचिन्त्योऽयमविकार्योऽयमुच्यते। तस्मादेवं विदित्वैनं नानुशोचितुमर्हसि

This Self is said to be unmanifested, unthinkable, and unchangeable. Therefore, knowing this to be so, you should not grieve.