Sanskrit
बाह्यस्पर्शेष्वसक्तात्मा विन्दत्यात्मनि यत्सुखम् । स ब्रह्मयोगयुक्तात्मा सुखमक्षयमश्नुते ॥
bāhyasparśeṣv asaktātmā vindaty ātmani yat sukham sa brahmayogayuktātmā sukham akṣayam aśnute
Translation
He, whose self is unattached to external contacts and findeth joy in the Self, having the self harmonised with the Eternal by yoga, enjoys imperishable bliss.
Annie Besant · The Bhagavad-Gita, translated by Annie Besant (4th ed., 1922) — Wikisource · Public Domain
Explanation
The pivot from external contacts to a happiness located within the Self is the hinge on which the rest of the chapter turns — everything from here to the end concerns a joy that doesn’t depend on what the senses touch. Akṣaya, imperishable, is doing precise work against the argument the next verse will make: sense-pleasures decay because they are compound events with a beginning and an end, while this inward happiness, being of the same nature as the Self, shares none of that structure. This is also the first clear anticipation of chapter 6’s meditation instructions, which will spend a dozen verses detailing exactly how the mind is drawn inward to find this same sukham.