Jamieson, Fausset and Brown on Isaiah 66:24

24. go forth, and look--as the Israelites looked at the carcasses of the Egyptians destroyed at the Red Sea (Ex 14:30; compare Is 26:14-19; Psa 58:10; 49:14; Mal 4:1-3).

carcasses, &c.--(Is 66:16), those slain by the Lord in the last great battle near Jerusalem (Zec 12:2-9; 14:2-4); type of the final destruction of all sinners.

worm ... not die--(Mr 9:44, 46, 48). Image of hell, from bodies left unburied in the valley of Hinnom (whence comes Gehenna, or "hell"), south of Jerusalem, where a perpetual fire was kept to consume the refuse thrown there (Is 30:33). It shall not be inconsistent with true love for the godly to look with satisfaction on God's vengeance on the wicked (Re 14:10). May God bless this Commentary, and especially its solemn close, to His glory, and to the edification of the writer and the readers of it, for Jesus' sake!