Verse 61

आत्मैवेदं जगदिति जाते राघव निश्चये ।असत्ता चेतसो जाता भवत्येव न संशयः

In plain words

O Rāghava, once the certainty has arisen that 'this world is ātman alone', the very non-existence of citta comes to be born -- of this there is no doubt at all.