9 Josephus has explained the origin of the priestly day-course ( ἐφημερίς) in Ant. 7.365-67, paraphrasing 1 Chr 24:1-19. According to the biblical story, near the end of his life King David recognized 24 clans among the priests descended from Aaron’s sons Eleazar and Ithamar, for service in the sanctuary. The first clan recognized by lot was that of Jehoiarib (Ioarib)—the clan from which the Hasmoneans would later spring ( Ant. 12.265; cf. 1 Macc 2:1). Although the Greek word ἐφημερίς ordinarily signified a diary (Plutarch, Caes. 22.2) or daily account book (Diogenes Laertius 6.86), Josephus reserves the word for the priestly courses, using it only here and in the passages given above. The LXX (e.g., 1 Chr 9:33; 23:6) has ἐφημερία. In Apion 2.108, extant only in Latin, Josephus will assert that there are “four tribes ( tribus) of priests.” Either he preserves there a recollection of the four priestly families who returned from exile (Ezra 2:36-39; Neh 7:39-42)—as y. Ta’an. 68a mentions both 4 and 24 courses—or the Latin reflects a textual corruption from 24. By Josephus’ time, a weekly rotation was in place ( Ant. 7.365). Each priestly course came up to Jerusalem from its home territory to serve from one sabbath to the next. Thus each course served twice per year in addition to the three pilgrimage festivals, when all eligible priests were required. References to this system are also found in Qumran texts (4Q320, 321: ET in Martinez, 1996:452-54), the NT (Luke 1:5-8), and rabbinic literature beginning with the Mishnah (e.g., m. Sukkah 5.6-8; m. Tamid 6.1-3; m. Ta’an. 5.6-7). For analysis, see Schürer-Vermes 2.245-50.