1 Chronicles 24:1-19
Now these are the divisions of the sons of Aaron. The sons of Aaron; Nadab, and Abihu, Eleazar, and Ithamar.
Torrey's Topical Textbook—AKJV

2 Chronicles 8:14
And he appointed, according to the order of David his father, the courses of the priests to their service, and the Levites to their charges, to praise and minister before the priests, as the duty of every day required: the porters also by their courses at every gate: for so had David the man of God commanded.
Torrey's Topical Textbook—AKJV

2 Chronicles 35:4,5
And prepare yourselves by the houses of your fathers, after your courses, according to the writing of David king of Israel, and according to the writing of Solomon his son.
Torrey's Topical Textbook—AKJV