Bhagwad Gita
Chapter 6, Verse 22
यं लब्ध्वा चापरं लाभं मन्यते नाधिकं ततः।
यस्मिन्स्थितो न दुःखेन गुरुणापि विचाल्यते।।6.22।।
Having obtained it, he thinks there is no other gain superior to it; established in it, he is not moved even by heavy sorrow.