सहजं कर्म कौन्तेय सदोषमपि न त्यजेत्। सर्वारम्भा हि दोषेण धूमेनाग्निरिवावृताः ॥

saha-jaṁ karma kaunteya sa-doṣham api na tyajet sarvārambhā hi doṣheṇa dhūmenāgnir ivāvṛitāḥ

Congenital duty, O son of Kunti, though defective, ought not to be abandoned. All undertakings indeed are clouded by defects as fire by smoke.

In plain words: Krishna tells Arjuna, "son of Kunti," not to give up the duty he was born to, even if it has flaws. Every kind of work has some fault, just as every fire gives off smoke.