Having commanded Arjuna to tolerate the dualities in Verse 14, Krishna now explains *why* this tolerance is necessary. He states that the person (puruṣaṃ) who is not agitated (na vyathayanti) by these sensory contacts, and who remains equal (sama) in both distress and happiness, is the one who becomes eligible (kalpate) for immortality or liberation (amṛtatvāya). He addresses Arjuna as 'Puruṣarṣabha' (best/bull among men), reminding him of his innate strength.