Revelation 6:10-11

They cried out with a loud voice, ‘Lord,  the one who is holy and true,  how long until you judge those who live on the earth and avenge our blood?   ’ So they were each given a white robe, and they were told to rest a little while longer until the number would be completed of their fellow servants and their brothers and sisters, who were going to be killed just as they had been.