Bhagavad Gita 6.27

Supreme bliss is the lot of the sage whose mind attains peace, whose passions subside, who is without sin, and who becomes one with the Absolute.

प्रशान्तमनसं ह्येनं योगिनं सुखमुत्तमम्।
उपैति शान्तरजसं ब्रह्मभूतमकल्मषम्॥

praśāntamanasaṃ hyenaṃ yoginaṃ sukhamuttamam|
upaiti śāntarajasaṃ brahmabhūtamakalmaṣam||

English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).