Bhagavatapurana 10.24.18

10.24.18

tasmāt sampūjayet karma svabhāva-sthaḥ sva-karma-kṛt /
anjasā yena varteta tad evāsya hi daivatam //

18. Continuing to be in his own nature every one ought to worship Karma and do his own duty; for only that (Karma) is his duty by which he can be well off (successful in life).