Revelation 6:9-10

Darby Translation

⁹ And when it opened the fifth seal, I saw underneath the altar the souls of them that had been slain for the word of God, and for the testimony which they held;

¹⁰ 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?