Bhagwad Gita
Chapter 6, Verse 27
प्रशान्तमनसं ह्येनं योगिनं सुखमुत्तमम्।
उपैति शान्तरजसं ब्रह्मभूतमकल्मषम्।।6.27।।
The yogi whose mind is fixed on Me verily attains the highest happiness. By virtue of his identity with Brahman, he is liberated; his mind is peaceful, his passions are quieted, and he is freed from sin.