Bhagavad Gita · 18.47

श्रेयान्स्वधर्मो विगुणः परधर्मात्स्वनुष्ठितात्।स्वभावनियतं कर्म कुर्वन्नाप्नोति किल्बिषम्॥

śhreyān sva-dharmo viguṇaḥ para-dharmāt sv-anuṣhṭhitāt svabhāva-niyataṁ karma kurvan nāpnoti kilbiṣham

Better is one's own duty, though imperfectly performed, than the duty of another well performed. One who does the duty ordained by one's own nature incurs no sin.

— Bhagavad Gita 18.47

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