1 Chronicles 25:8

8. They cast lots, ward against ward The word rendered ward means a charge, a guardianship or superintendency. They cast lots to determine the order in which these different classes of singers should serve in the holy service, one class having charge until succeeded in the regular order by another. Our translators have repeated the word ward, but the Hebrew text reads literally: They cast lots for the charge, in the same manner as the small so the great, the skilled with the scholar. Of the four thousand Levites appointed for the service of song, (1 Chronicles 23:5,) the two hundred and eighty eight represented in 1 Chronicles 25:9-31 were the skilled ones, (“all that were cunning,” 1 Chronicles 25:7.) And these were so arranged and distributed by lot that the rest of the four thousand (3,712) were amply supplied with teachers, there being one teacher for about thirteen scholars. So both the small and great, (that is, the older and the younger, comp. 1 Chronicles 24:31,) the teachers and the scholars, were divided into classes, and distributed by lot.