According to John Welch, certain numbers were clearly meaningful in antiquity: seven was the number of spiritual perfection (as in the seven seals in the book of Revelation); twelve was a governmental number (as with the twelve tribes, twelve apostles). The number twenty-four, being a multiple of twelve, was associated with heavenly government, especially priestly judgment and temple service. . . . Twenty-four courses of priests continuously operated Davidic tabernacle and Solomonic temple services (see 1 Chronicles 24:3-18) . . . Apparently there were twenty-four judges on King Noah's court, since Noah and his priests kidnapped twenty-four Lamanite daughters (see Mosiah 20:5).
Turning to other places in the Book of Mormon, we see that twenty-four has remarkably similar significance (Listed below are only 3 of 8 listed by Welch):
1. There were twenty-four survivors of the final destruction of the Nephites who witnessed the judgment of God upon this people (see Mormon 6:11, 15, 22).
2. The twenty-four plates of Ether were seen as a record of the "judgment of God" upon those people (Alma 37:30).
3. Like the twelve apostles of the Old World, the twelve Nephite disciples (for a total of twenty-four) will act as judges in the final judgment of the world (see 3 Nephi 27:27).
[John W. Welch, "Number 24," in Reexploring the Book of Mormon, F.A.R.M.S., p. 272]