Mahabharata 12.297.9

असता धर्मकामेन विशुद्धं कर्म दुष्करम्सता तु धर्मकामेन सुकरं कर्म दुष्करम्

asatā dharmakāmena viśuddhaṃ karma duṣkaramsatā tu dharmakāmena sukaraṃ karma duṣkaram

Our plain-language meaning of this verse is waiting for scholar review.