Bhagavad Gita: Chapter 2, Verse 55

श्रीभगवानुवाच
प्रजहाति यदा कामान्सर्वान्पार्थ मनोगतान् ।
आत्मन्येवात्मना तुष्टः स्थितप्रज्ञस्तदोच्यते ॥ २-५५ ॥

śrī-bhagavān uvāca
prajahāti yadā kāmān sarvān pārtha mano-gatān
ātmany evātmanā tuṣṭaḥ sthita-prajñas tadocyate 2.55

Sri Bhagawan Said: O Pārtha when a man gives up all varieties of desire for sense gratification, which arise from mental concoction, and when his mind, thus purified, finds satisfaction in the self alone, then he is said to be in pure transcendental consciousness.