SB 4.20.8
ya evam santam atmanam
atma-stham veda purusah
najyate prakrti-stho ’pi
tad-gunaih sa mayi sthitah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Although within the material nature, one who is thus situated in full knowledge of the Paramatma and atma is never affected by the modes of material nature, for he is always situated in My transcendental loving service.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
When the Supreme Personality of Godhead appears in this material world, He is not affected by the modes of material nature. Similarly, those who are always connected with the Supreme Personality of Godhead, even though they be within the material body or the material world, are not affected by the material qualities. That is explained very nicely in Bhagavad-gita (14.26):
mam ca yo ’vyabhicarena
bhakti-yogena sevate
sa gunan samatityaitan
brahma-bhuyaya kalpate
“One who is unflinchingly engaged in the devotional service of the Lord surpasses the material qualities and attains Brahman realization.” In this connection Srila Rupa Gosvami says that if a person is always engaged in the service of the Lord with his body, words and mind, he is to be considered liberated although living in the material world.