Revelation 7:9-14

9After these things I looked, and behold, a vast multitude that no one could count—from every nation and all tribes and peoples and tongues—was standing before the throne and before the Lamb. They were clothed in white robes, with palm branches in their hands

10and crying out with a loud voice, saying, “Salvation belongs to our God, who sits on the throne, and to the Lamb!”

11And all the angels were standing around the throne, along with the elders and the four living creatures; and they fell on their faces before the throne and worshiped God,

12saying, “Amen, blessing and glory and wisdom and thanksgiving and honor and power and might belong to our God forever and ever. Amen!”

13Then one of the elders answered, saying to me, “Who are these dressed in white robes, and where have they come from?” I said to him, “Sir, you know.”

14Then he said to me, “These are the ones coming out of the great tribulation. They have washed their robes and made them white in the blood of the Lamb.