'On the Sabbath' in the Bible

Observe, I am about to build a house for the Name of the Lord my God, dedicated to Him, to burn fragrant incense [of sweet spices] before Him, to set out the showbread continually, and to offer burnt offerings morning and evening, on Sabbaths, New Moons, and on the festivals of the Lord our God, as ordained forever in Israel.

This is what you shall do: a third of you, of the priests and Levites who are resuming service on the Sabbath, shall be gatekeepers,

So the Levites and all Judah acted in accordance with everything that Jehoiada the priest had commanded; and every man took his men who were to resume duty on the Sabbath, with those who were to go off duty on the Sabbath, for Jehoiada the priest did not dismiss [any of] the divisions [from their duties].