'Courses' in the Bible

And David distributeth them into courses: Of the sons of Levi: of Gershon, Kohath, and Merari.

And to the sons of Aaron are their courses: sons of Aaron are Nadab, and Abihu, Eleazar, and Ithamar,

For the courses of the gatekeepers: of the Korhites is Meshelemiah son of Kore, of the sons of Asaph;

According to these are the courses of the gatekeepers; to the heads of the mighty ones are charges over-against their brethren, to minister in the house of Jehovah,

These are the courses of the gatekeepers, of the sons of the Korhite, and of the sons of Merari.

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.

and for the courses of the priests and of the Levites, and for all the work of the service of the house of Jehovah, and for all vessels of service of the house of Jehovah,

And lo, courses of the priests and of the Levites are for all the service of the house of God; and with thee in all work is every willing one with wisdom, for every service; and the heads and all the people are according to all thy words.'