Bhagavad Gita 18.47
श्रेयान्स्वधर्मो विगुणः परधर्मात्स्वनुष्ठितात् । स्वभावनियतं कर्म कुर्वन्नाप्नोति किल्बिषम् ॥
śreyān sva-dharmo viguṇaḥ para-dharmāt sv-anuṣṭhitāt / svabhāva-niyataṃ karma kurvan nāpnoti kilbiṣam
Translation
Better is one's own dharma though imperfect, than another's dharma well performed. Doing the work determined by one's own nature, one does not incur sin.
Reflection
Whose calling have you been performing well at the cost of your own?
Read this verse in its chapter: Chapter Eighteen
The Gita repeats this verdict from chapter three because it cannot be said too often. Sva-dharma even vigunah, with flaws, beats para-dharma even sv-anushthitah, beautifully performed. The principle is not that imperfection is virtuous. The principle is that the act stretched out of one's actual nature, however polished, costs more than it pays. Svabhava-niyatam karma, the work that one's own nature settles, performed by that nature, does not generate kilbisha, the residue of wrongdoing. This is the Gita's defense of vocational truth. Borrowed callings, even prestigious ones, distort. One's own calling, even unimpressive, refines. The verse cuts every imitation career down to size.