'Courses' in the Bible

The divisions of the descendants of Aaron were these: the sons of Aaron were Nadab, Abihu, Eleazar, and Ithamar.

David assembled at Jerusalem all the leaders (officials) of Israel, the leaders of the tribes, and the commanders of the divisions that served the king, and the commanders of thousands, and the commanders of hundreds, and the overseers of all the property and livestock of the king and his sons, with the palace officers and the mighty men, and all the brave warriors.