'Serving' in the Bible

And the sons of Israel, after their number, heads of the fathers, and princes of the thousands and of the hundreds, and their officers, those serving the king in any matter of the courses, that are coming in and going out month by month, throughout all months of the year -- are in each course twenty and four thousand.

And David assembleth all the heads of Israel, heads of the tribes, and heads of the courses who are serving the king, and heads of the thousands, and heads of the hundreds, and heads of all the substance and possessions of the king, and of his sons, with the officers and the mighty ones, even to every mighty one of valour -- unto Jerusalem.