Bhagavad Gita 2.55
Lord Shri Krishna replied: When a person has given up the desires of their heart and is content with the Self alone, they have surely reached the highest state.
श्री भगवानुवाच
प्रजहाति यदा कामान् सर्वान् पार्थ मनोगतान्।
आत्मन्येवात्मना तुष्टः स्थितप्रज्ञस्तदोच्यते॥śrī bhagavānuvāca
prajahāti yadā kāmān sarvān pārtha manogatān|
ātmanyevātmanā tuṣṭaḥ sthitaprajñastadocyate||
English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).