Revelation 16:4-7 RSV

4 The third angel poured his bowl into the rivers and the fountains of water, and they became blood.
5 And I heard the angel of water say, "Just art thou in these thy judgments, thou who art and wast, O Holy One.
6 For men have shed the blood of saints and prophets, and thou hast given them blood to drink. It is their due!"
7 And I heard the altar cry, "Yea, Lord God the Almighty, true and just are thy judgments!"