'Duty' in the Bible

They kept also the feast of tabernacles, as it is written, and offered the daily burnt offerings by number, according to the custom, as the duty of every day required;

Let it now be known to the king that if that city is rebuilt and its walls are finished, they will not pay tribute, duty, or land tax, and the royal revenue will suffer.

Powerful kings have also ruled over Jerusalem and exercised authority over the whole region, and tribute, duty, and land tax were paid to them.

Be advised that tribute, duty, and land tax must not be imposed on any priests, Levites, singers, doorkeepers, temple servants, or other servants of this house of God.

Stand up, for it is your duty, and we will be with you. Be brave and act.”

Then all the assembly replied with a loud voice, “That’s right! As you have said, so it is our duty to do.