Chronicles I 23:24

24 These the sons of Levi according to the houses of their fathers; chiefs of their families according to their numbering, according to the number of their names, according to their polls, doing the works of service of the house of the Lord, from twenty years old and upward.

Chronicles I 23:24 Meaning and Commentary

1 Chronicles 23:24

These were the sons of Levi, after the house of their fathers,
&c.] According to the three classes of them, as descending from the three sons of Levi:

[even] the chief of the fathers;
or heads of families:

as they were counted by number of names by their polls;
or according to their heads, one by one:

that did the work for the service of the house of the Lord;
the particulars of which are in ( 1 Chronicles 23:28-31 )

from the age of twenty years, and upwards;
they were first numbered thirty and upwards, ( 1 Chronicles 23:3 ) , but David before his death ordered they should be numbered from twenty and upwards, ( 1 Chronicles 23:27 ) , because the Israelites being increased, there would be more work for the priests in the temple, which would require the assistance of more Levites. The reasons follow.

Chronicles I 23:24 In-Context

22 And Eleazar died, and he had no sons, but daughters: and the sons of Kis, their brethren, took them.
23 The sons of Musi; Mooli, and Eder, and Jarimoth, three.
24 These the sons of Levi according to the houses of their fathers; chiefs of their families according to their numbering, according to the number of their names, according to their polls, doing the works of service of the house of the Lord, from twenty years old and upward.
25 For David said, The Lord God of Israel has given rest to his people, and has taken up his abode in Jerusalem for ever.
26 And the Levites bore not the tabernacle, and all the vessels of it for its service.

The Brenton translation of the Septuagint is in the public domain.