B.G 2.15

yaṁ hi na vyathayantyete puruṣaṁ puruṣarṣabha। samaduḥkhasukhaṁ dhīraṁ so'mṛtatvāya kalpate ॥ 2-15॥

O best among men, the person who remains undisturbed by these, who is equanimous in both pain and pleasure, and steadfast, is indeed fit for immortality.

Gīta Bhāshya 2.15

By bravery one can learn to react with equanimity.

ataḥ prayojanamāha yaṃ hi iti॥ yam ete mātrāsparśā na vyathayanti। puri śayameva santam। śarīrasambandhābhāve sarveṣāmapi vyathābhāvāt puruṣam iti viśeṣaṇam। kathaṃ na vyathayanti? samaduḥkhasukhatvāt। tatkatham? dhairyeṇa ॥ 15 ॥

Its (overcoming self-attachment) practical use is stated by 'yam hi' verse. The person referred here is the one who does not get perturbed by the contact of sensations. Monk is the one who has the ability to sleep in the body with detachment. [Here 'Puri' means body.] Because of sentiment of association with body one who is perturbed all the time is specially called 'purusha'. How can one overcome this disturbance? Having equanimity towards pain and pleasure. How? By bravery.

Gīta Tātparya 2.15

One can defeat death only by becoming 'Purusha', i.e., understanding auspicious qualities of the Lord.

phalam āha। yaṁ hīti। na kevalam avyathāmātreṇāmṛtatvaṁ kintu puruṣam।

The benefit is described in 'yam hi' verse. One cannot defeat death just by getting rid of misery. One can defeat it by becoming 'purusha'.

"puru brahma guṇādhikyāt tajjñānātpuruṣaḥ smṛtaḥ"

"Brahman is called 'pura' because of increased auspicious qualities. One who has such knowledge of Brahman is called 'Purusha'".

iti pravṛtte।

–thus states ancient text Pravrutti.

purusaraṇāt puruṣa ityarthaḥ ॥15॥

One who possesses the knowledge of auspicious qualities is the meaning of 'Purusha'.