B.G 5.24

योऽन्तःसुखोऽन्तरारामस्तथान्तर्ज्योतिरेव यः। स योगी ब्रह्मनिर्वाणं ब्रह्मभूतोऽधिगच्छति ॥२४॥

He alone has the inner radiance whose has inner happiness and inner rest. That practitioner of Yōga being situated in Brahman attains liberation in Brahman.

Gīta Bhāshya 5.24

The characteristics of a 'jnānin' in subsequent verses. 'ārāmaḥ', i.e. pleasure, is the happiness derived from seeing others. 'sukha', i.e. happiness, is used to indicate the visible state that manifests when cessation of disturbances happens. 'antarjyoti', i.e. inner radiance, is because of the divine lord. The word 'eva', i.e. 'he alone', indicates exclusivity to the individual, and also the finiteness of such a person. The cause of inner happiness is because of 'brahmaṇi bhūta' , i.e. being situated in Brahman.

ज्ञानिलक्षणं प्रपञ्चयति उत्तरैः श्लोकैः।आरामः परदर्शनादिनिमित्तं सुखम्। अत्र तु परमात्मदर्शनादि निमित्तं तत्। सुखं तु उपद्रवक्षये व्यक्तम्। अत्र तु कामादिक्षये व्यक्तम् आत्मनः सुखम्। स्वयम् ज्योतिष्ट्वात् भगवतः। तद्व्यक्तेः अन्तर्ज्योतिः। सर्वेषाम् अन्तर्ज्योतिष्ट्वेऽपि व्यक्तेर्विशेषः। असम्प्रज्ञातसमाधीनां बाह्यादर्शनात्। दर्शनेऽपि अङ्किचित्करत्वात् एवशब्दः। उक्तं चैतत्-

The characteristics of a 'jnānin' are described in subsequent verses. The word 'ārāmaḥ', i.e. pleasure, is the happiness derived from seeing others. In the current context, it is because of seeing the supreme lord there! The word 'sukha', i.e. happiness, is used to indicate the visible state that manifests when cessation of disturbances happens. In this context, certainly, cessation of desire and such defects manifests in happiness of the self. Oneself experiences radiance because of the divine lord. That manifestation is termed 'antarjyoti', i.e. inner radiance. Of all, the word 'antarjyoti', i.e. 'inner radiant', is used as an adjective to indicate the speciality of such an individual. The one in 'asamprajñātasamādhī', i.e. equilibrium state without conscious awareness, will not have external perception. Even with such perception, his being is limited, hence the word 'eva', i.e. 'he alone', is used. Hence, it is said:

"दर्शनस्पर्शसम्भाषादयात्सुखं जायते नृणाम्। आरामः स तु विज्ञेयः सुखं कामक्षयोदितम्॥"

"The happiness that arises in people from seeing, touching, conversing, etc. is 'ārāma'. 'sukha' is to be known as that happiness which arises due to cessation of desire."

इति नारदीये।

- stated thus in Nārada Purāna.

"स्वज्योतिष्ट्वान्महाविष्णोरन्तर्ज्योतिस्तु तत्स्थितः।"

"The great lord Vishnu is self radiant. Indeed, he is 'inner-radiant' in whom He is situated."

इति च।

- stated thus as well (in Nārada Purāna).

अन्तःसुखादेः कारणमाह - ब्रह्मणि भूत इति ॥२४॥

The cause of inner happiness is indicated by stating 'brahmaṇi bhūta' , i.e. being situated in Brahman.

Gīta Tātparya 5.24

The inner happiness and such attributes are because of the vision of Brahman.

ब्रह्मणि भूतः। अन्यथा पुनः ब्रह्म गच्छतीति विरोधाच्च। अन्तःसुखादिकं च ब्रह्मदर्शनात् ॥२४॥

The word 'brahmaṇi' goes as per grammer with 'bhūtaḥ'. Otherwise, attainment of Brahman gets repeated and is redundant and thus contrary to Sanskrit's traditional way of writing.

The inner happiness and such attributes are because of the vision of Brahman.