ISB ~ Revelation 4 v4

twenty-four elders:Represent the saints, who are dressed like priests (in white) and kings (with crowns). See note on Rev 1:6.

• Their number symbolizes the 24 priestly rotations that David established to minister in the Temple (1 Chron 24:1-31). In Jewish tradition, the heads of the 24 divisions were called “elders”.

Some see the elders representing the fullness of the royal priestly people of God:the 12 tribes of the sons of Israel (saints of the OT) plus the 12 apostles of Christ (saints of the NT), as in the vision of 21:12-14.