बाह्यस्पर्शेष्वसक्तात्मा विन्दत्यात्मनि यत्सुखम् | स ब्रह्मयोगयुक्तात्मा सुखमक्षयमश्नुते ||५-२१||
bāhyasparśeṣvasaktātmā vindatyātmani yatsukham . sa brahmayogayuktātmā sukhamakṣayamaśnute ||5-21||
5.21. The enjoyments that are born of contacts [with objects] are indeed nothing but sources of misery and have beginning and end. [Hence], an intelligent man does not get delighted in them, O son of Kunti !
Shri Purohit Swami
5.21 He finds happiness in his own Self, and enjoys eternal bliss, whose heart does not yearn for the contacts of earth and whose Self is one with the Everlasting.
Sri Abhinav Gupta
5.21 He, in whom there is no desire for the external touch viz., the object-he thinks says as follows the Bhagawat -
5.21 He who finds happiness in the self within himself, his mind detached from external contact in the manner already mentioned, i.e., from experience of objects other than the self - such a person abandoning the contemplation on Prakrti or bodily experiences, has his mind engaged in the contemplation on Brahman i.e., the Atman. Thus he attains everlasting bliss which consists in the experience of Brahman (the self).
Sri Krsna speaks of the abandonment of material pleasure as easy:
5.21 Asakta-atma, with his heart, internal organ, unattached, bahya-sparsesu, to external objects-sparsah means objects that are contacted, viz sound etc.; bahya-sparsah means those things which are external (bahya) and are objects of contact; that person who thus has his heart unattached, who derives no happiness from objects; he vindati, gets that sukham, bliss; yat, which is; atmani, in the Self. Brahma-yoga-yukta-atma, with his heart absorbed in meditation on Brahman-meditation (yoga) on Brahman is brahma-yoga; one whose internal organ (atma) is absorbed in (yukta), engaged in, that meditation on Brahman is brahma-yoga-yukta-atma; he asnute, acires; aksayam, undecaying; sukham, Bliss. So, he who cherishes undecaying happiness in the Self should withdraw the organs from the momentary happiness in external objects. This is the meaning. For this reason also one should withdraw:
5.21 He whose mind is detached from external contact, and finds happiness in the self - he has his mind engaged in the contemplation of Brahman and he enjoys undecaying bliss.
5.21 With his heart unattached to external objects, he gets the bliss that is in the Self. With his heart absorbed in meditation on Brahman, he acires undecaying Bliss.
5.21 With the self unattached to external contacts he finds happiness in the Self; with the self engaged in the meditation of Brahman he attains to the endless happiness.
5.21 बाह्यस्पर्शेषु in external contacts? असक्तात्मा one whose mind is unattached? विन्दति finds? आत्मनि in,the Self? यत् (that) which? सुखम् happiness? सः he? ब्रह्मयोगयुक्तात्मा with the self engaged in the meditation of Brahman? सुखम् happiness? अक्षयम् endless? अश्नुते enjoys.Commentary When the mind is not attached to external objects of the senses? when one is deeply engaged in the contemplation of Brahman? he finds undecaying bliss in the Self within. If you want to enjoy the imperishable happiness of the Self within? you will have to withdraw the senses from their respective objects and plunge yourself in deep meditation on the Self within. This is the gist of this verse.