Luk 18:2-8 saying, A certain judge was in a certain city, not fearing God, nor respecting man. (3) And a widow was in that city. And she came to Him, saying, Avenge me of my adversary. (4) And he would not do so for a time. But afterward he said within himself, Though I do not fear God nor regard man, (5) yet because this widow troubles me, I will avenge her, that she not wear me down in the end. (6) And the Lord said, Hear what the unjust judge says. (7) And shall not God avenge His own elect who cry day and night to Him, though He has been long-suffering over them? (8) I say to you that He will avenge them speedily. Yet when the Son of Man comes, shall He find faith on the earth?

Rev 6:10 And they cried with a loud voice, saying, Until when, Master, holy and true, do You not judge and avenge our blood on those who dwell on the earth?