Revelation 6:10-11

and they cried with a loud voice, saying, How long, O sovereign Ruler, holy and true, dost thou not judge and avenge our blood on them that dwell upon the earth? And there was given to them, to each one a white robe; and it was said to them that they should rest yet a little while, until both their fellow-bondmen and their brethren, who were about to be killed as they, should be fulfilled.