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बाह्यस्पर्शेष्वसक्तात्मा विन्दत्यात्मनि यत् सुखम् ।
स ब्रह्मयोगयुक्तात्मा सुखमक्षयमश्नुते ॥५- २१॥

baahyasparsheShwasaktaatmaa windatyaatmani yat sukham ।

sa brahmayogayuktaatmaa sukhamakShayamashnute ॥५- २१॥

Source: Automatic ITRANS Transliteration

The self unaddicted to external contacts, who derives happiness from the self:

That yoga-adherent Brahma self enjoys eternal happiness.

Source: Milind S. Pandit

A person whose mind is unattached to sensual pleasures, who discovers the joy of the Self, and whose mind is in union with Brahman through meditation, enjoys eternal bliss.

Source: The Bhagavad-Gita: The Sacred Song

Such a liberated person is not attracted to material sense pleasure or external objects but is always in trance, enjoying the pleasure within. In this way the self-realized person enjoys unlimited happiness, for he concentrates on the Supreme.

Source: Bhagavad Gita As It Is