After this I looked, and the sanctuary of the tent of witness in heaven was opened,
Observe, I. How these angels appeared - coming out of heaven to execute their commission: The temple of the tabernacle of the testimony in heaven was opened, Rev 15:5. Here is an allusion to the holiest of all the tabernacle and temple, where was the mercy-seat, covering the ark of the testimony, where the high priest made intercession, and God communed with his people, and heard their prayers.
Commenting on Revelation 15:5-8
And after that I looked,.... That is, after John had seen the above vision, he looked again, and saw what follows: and behold, the temple of the tabernacle of the testimony in heaven was opened; this does not refer to heaven itself, the antitype of the holy of holies, which is opened by the blood of Christ, by which he himself has entered, and his...
Verse 5. And after that I looked. After I had seen in vision the redeemed thus referred to, celebrating the praises of God, I saw the preparation made for the execution of these purposes of judgment. And, behold, the temple of the tabernacle of the testimony.