Chapter 5 · The Yoga of Renunciation · Krishna said
Bhagavad Gita 5.21 — Joy within
बाह्यस्पर्शेष्वसक्तात्मा विन्दत्यात्मनि यत्सुखम्। स ब्रह्मयोगयुक्तात्मा सुखमक्षयमश्नुते ॥
bāhyasparśeṣvasaktātmā vindatyātmani yatsukham | sa brahmayogayuktātmā sukhamakṣayamaśnute ||
Meaning
One unattached to outer sense contacts finds joy within the Self. United with Brahman through yoga, he enjoys happiness that never ends.