'Duty' in the Bible

Then Judah said to Onan, "Go in to the wife of your brother and perform the duty of a brother-in-law to her, and raise up offspring for your brother."

"When brothers dwell together and one of them dies and has no son, the wife of the deceased shall not become the wife of a {man of another family}; her brother-in-law {shall have sex with her}, and he shall take her {to himself} as wife, and he shall perform his duty as brother-in-law [with respect to] her.

He commanded them, saying, "This [is] the thing which you must do: one third of you {who go off duty on the Sabbath}, the keepers of the guard in the house of the king,

Two of the units among you, all {who go on duty on the Sabbath}, guard the post of the temple of Yahweh for the king.

So the commanders of hundreds did according to all that Jehoiada the priest commanded, and each took his men {who went off duty on the Sabbath} and those {who came on duty on the Sabbath}, and they came to Jehoiada the priest.

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:

And it was the primary [duty] of the trumpeters and singers to make themselves heard [with] one voice, to praise and give thanks to Yahweh. And when a sound from the trumpets, cymbals, and other instruments of song was raised to Yahweh--for he [is] good, because his loyal love [is] everlasting--then the house, the house of Yahweh, was filled with a cloud.

and the food of his table, and the position of his officers, the duty of his servants and their clothing, his cupbearers and their clothing, and his burnt offerings that he offered at the house of Yahweh, there was no longer any breath in her.

This is the thing that you must do: one third of you priests and Levites {coming off duty on the Sabbath} [shall be] gatekeepers at the entrances

And the Levites and all Judah did according to all that Jehoiada the priest commanded. And they each took his men [who were] {coming off duty on the Sabbath} with {the ones going out to duty on the Sabbath}, for Jehoiada the priest did not dismiss the working groups.

Mighty kings have ruled over Jerusalem, [governing] all [the province] Beyond the River, to whom tribute, duty, and tax has been given.

You also should be aware that it is not permitted to place tax, tribute, or duty upon all of the priests, the Levites, the singers, the doorkeepers, the temple servants, and other servants of the house of God.

Now that all has been heard, here is the final conclusion: Fear God and obey his commandments, for this [is] the whole [duty] of man.

{And when} he [was] at the Gate of Benjamin, there [was] {a sentry on duty} whose name [was] Irijah, the son of Shelemiah, the son of Hananiah, and he seized Jeremiah the prophet, {saying}, "You [are] deserting to the Chaldeans!"