Revelation 6:9-11 - The Fifth Seal
9 When the Lamb opened the fifth seal, I saw under the altar the persons who were slaughtered because of the word of God, and for the witness they gave. 10 They cried with a loud voice, saying: How long, O Lord, holy and true, before you judge and avenge our blood on those who dwell on the earth? 11 Each of them was given a white robe. They were told that they should rest for a little while. [They were to wait] until the [number] of their fellow servants and their brothers, who would be killed, as they were, should be fulfilled.