इहैव तैर्जितः सर्गो येषां साम्ये स्थितं मनः। निर्दोषं हि समं ब्रह्म तस्माद्ब्रह्मणि ते स्थिताः ॥

ihaiva tair jitaḥ sargo yeṣhāṁ sāmye sthitaṁ manaḥ nirdoṣhaṁ hi samaṁ brahma tasmād brahmaṇi te sthitāḥ

Even here on earth everything is overcome by those whose mind remains balanced; the Eternal is incorruptible and balanced; therefore they are established in the Eternal.

In plain words: Krishna says that people whose minds stay calm and fair toward all have already won over life, even while living on earth. God, the Eternal, is pure and the same toward everyone, so people who are balanced like that live in God.