The four and twenty elders fall down before him that sat on the throne, and worship him that liveth forever and ever. Shall fall, etc. The tenses are all future except the present "sitteth" and "liveth."
The four and twenty elders are the representatives of the universal Church (see on Revelation 4:4). And cast their crowns before the throne, saying. Their crowns of victory, στεφάνους (see on Revelation 2:10 and Revelation 4:4).