Bhagavad Gita · 14.26

मां च योऽव्यभिचारेण भक्तियोगेन सेवते।स गुणान्समतीत्यैतान्ब्रह्मभूयाय कल्पते॥

māṁ cha yo 'vyabhichāreṇa bhakti-yogena sevate sa guṇān samatītyaitān brahma-bhūyāya kalpate

One who serves me with unwavering devotion, transcending these three gunas, becomes fit to realize Brahman.

— Bhagavad Gita 14.26

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)