After this I looked, and the temple in heaven—that is, the tent of witness—was opened.
References for Revelation 15:5
The seven angels, who have the seven plagues, came out of the temple. They were clothed in pure bright linen and had gold sashes around their waists.
Then one of the four living creatures gave the seven angels seven gold bowls full of the anger of the God who lives forever and always.
The temple was filled with smoke from God's glory and power, and no one could go into the temple until the seven plagues of the seven last angels were brought to an end.