'Duty' in the Bible

They were ministering with song before the tabernacle of the tent of assembly until Solomon built the temple of Yahweh in Jerusalem. And they stood according to their order with respect to their duty.

And David and the commanders of the army set apart for the service the sons of Asaph, [of] Heman, and [of] Jeduthun, who prophesied with stringed instruments, with harps, and with cymbals. And their inventory of the men of the work [and] for their duty was: