Verse 57

आत्मनो व्यतिरिक्तं सच्चित्तमित्यङ्ग संविदा ।मनः संपद्यते दुःखि क्षीयते त्यक्तया तया

In plain words

Dear one, by the conviction that citta is something real yet other than ātman, mind becomes sorrowful; and with that very conviction abandoned, it wastes away.