19And the temple of God which is in heaven was opened; and the ark of His covenant appeared in His temple, and there were flashes of lightning and sounds and peals of thunder and an earthquake and a great hailstorm.
Rev_11:19 "the temple of God which is in heaven was opened" Remember that this vision began with a door being opened in heaven (cf. Rev_4:1; Rev_15:5). Now, the very inner sanctum of God's heavenly temple can be seen (cf. Heb_8:5; Heb_9:23-28).
When Jesus died the veil of the Temple was torn from top to bottom, indicating that access to God was now available to all through Christ (cf. Mat_27:51; Mar_15:38; Luk_23:45; alluded to in Heb_9:8; Heb_10:20). This same symbolism is repeated here. God is available to all. Heaven's inner sanctum is now fully open and visible.
▣ "the ark of His covenant" The ark of the covenant was lost sometime during the Babylonian Exile (or to Pharaoh Shishak of Egypt, cf. 1Ki_14:25). It symbolized the presence of God after Israel's crossing of the Jordan River into the Promised Land. It also symbolized God's covenant promises, which may refer to the mystery (cf. Rev_10:7), God's plan of redemption for all mankind (cf. Rom_16:25-26). In the OT only the High Priest could approach this article of holy furniture, once a year on the Day of Atonement (cf. Leviticus 16). Now, all of God's people can come into the very presence of God.
▣"flashes of lightning and sounds of peals of thunder and an earthquake and a great hailstorm" This is very similar to Rev_8:5; Rev_16:18-21, which reflect Exo_9:24; Exo_19:16-19.