'Obligations' in the Bible

He may minister to his brothers at the Tent of Meeting by keeping watch, but he is not to engage in service. This is how you are to act with respect to the obligations of the descendants of Levi."

and her father hears her vow and the obligations that she had pledged herself to fulfill, yet her father keeps silent about it, then all her vows and every obligation she pledged herself to are to stand.

But if her husband remains silent about her from day to day, then he has affirmed all her vows or obligations that she has obligated herself to fulfill. He has affirmed them because he remained silent from the day he heard her vows.

without regard to genealogical enrollment, to every male 30 years old and older that is, to everyone who entered the LORD's Temple as their duty obligations required for their work and duties according to their divisions

They carried out their service obligations to their God and their service obligations of purification according to what David and his son Solomon had commanded.