'Duty' in the Bible

When his division was on duty and he was serving as priest before God,

And He answered, “Why did you have to look for Me? Did you not know that I had to be in My Father’s house?”

and forgive us our sins, for we ourselves also forgive every one who fails in his duty to us; and bring us not into temptation.'"

Or those eighteen on whom the tower at Siloam fell, do you suppose they had failed in their duty more than all the rest of the people who live in Jerusalem?

So likewise ye, when ye shall have done all those things which are commanded you, say, We are unprofitable servants: we have done that which was our duty to do.