Courses
Courses refers to the rotational divisions David established for the priests and Levites in preparation for the temple service. Unable to build the temple himself, David organized the priestly clans into twenty-four courses or divisions, each responsible for temple service for one week twice annually (1 Chronicles 24:1–18). The Levitical singers and gatekeepers were similarly organized into corresponding courses (1 Chronicles 25–26). The system was activated when Solomon dedicated the temple and continued through the period of the monarchy.
The course system was restored after the exile (Nehemiah 12:1–26; 13:30) and was still functioning in New Testament times. Luke 1:5 notes that Zechariah, the father of John the Baptist, was a priest of the course of Abijah — the eighth of the twenty-four courses — serving in the temple when the angel Gabriel appeared to him. The course of Abijah's duty in the temple thus provides the chronological anchor for Luke's infancy narrative and for attempts to date the birth of John the Baptist and subsequently of Jesus.