'Avenge the Blood of' in the Bible

"Sing for joy, nations! Sing for joy, people who belong to him! For he'll avenge the blood of his servants, turn on his adversary, and cleanse both his land and his people."

You are to attack the household of your master Ahab, so I may avenge the blood of my servants the prophets, as well as the blood of all of the servants of the LORD that has been spilled at Jezebel's orders.