This is the list of the Israelites--the heads of families, the commanders of thousands and of hundreds, and their officers who served the king in every matter concerning the divisions on rotating military duty each month throughout the year. There were 24,000 men in each division:

1 Chronicles 26:32
Among Jerijah's relatives there were 2,700 capable men who were heads of families. King David appointed them over the Reubenites, the Gadites, and the half-tribe of Manasseh for every matter pertaining to God and to the affairs of the king.

1 Chronicles 27:2
Jashobeam son of Zabdiel was in charge of the first division, which was assigned the first month. There were 24,000 men in his division.

1 Chronicles 28:1
Now David summoned all the leaders of Israel to Jerusalem: the leaders of the tribes, the leaders of the divisions in the king's service, the commanders of thousands and of hundreds, and the officials in charge of all the property and cattle of the king and his sons, along with the court officials and mighty men--every mighty man of valor.

1 Chronicles 29:6
Then the leaders of the households, the officers of the tribes of Israel, the commanders of thousands and of hundreds, and the officials in charge of the king's work gave willingly.

Now the children of Israel after their number, to wit, the chief fathers and captains of thousands and hundreds, and their officers that served the king in any matter of the courses, which came in and went out month by month throughout all the months of the year, of every course were twenty and four thousand.