Bhagavad Gita 4.39

श्रद्धावान् लभते ज्ञानं तत्पर: संयतेन्द्रिय: |
ज्ञानं लब्ध्वा परां शांतिमचिरेणाधिगच्छति

Translation

Those whose faith is deep and who have practiced controlling their mind and senses attain divine knowledge. Through such transcendental knowledge, they quickly attain everlasting supreme peace.