Bhagavad Gita · 2.55

श्रीभगवानुवाचप्रजहाति यदा कामान्सर्वान्पार्थ मनोगतान्।आत्मन्येवात्मना तुष्टः स्थितप्रज्ञस्तदोच्यते॥

śhrī bhagavān uvācha prajahāti yadā kāmān sarvān pārtha mano-gatān ātmany evātmanā tuṣhṭaḥ sthita-prajñas tadochyate

The Supreme Lord said: O Partha, when one completely casts off all desires of the mind and is satisfied in the Self by the Self alone, then one is said to be of steady wisdom.

— Bhagavad Gita 2.55

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