Mandukya Karika 3.46
Sanskrit Verse
यदा न लीयते चित्तं न च विक्षिप्यते पुनः ।
अनिङ्गनमनाभासं निष्पन्नं ब्रह्म तत्तदा ॥ ४६ ॥
Transliteration
yadā na līyate cittaṃ na ca vikṣipyate punaḥ |
aniṅganamanābhāsaṃ niṣpannaṃ brahma tattadā || 46 ||
Translation
When the mind does not merge in the inactivity of oblivion, or become distracted by desires, that is to say, when the mind becomes quiescent and does not give rise to appearances, it verily becomes Brahman.

Muni's Play