'Avenge' in the Bible

So when Abner returned to Hebron, Joab took him aside to the middle of the gate to speak to him privately, and there he struck Abner in the abdomen so that he died, to avenge the blood of Asahel, Joab’s brother.

How much worse will it be, then, when evil men kill an innocent man on his own bed in his own house! Shouldn't I avenge his blood which you are responsible for shedding by removing you from the earth?"

Now the entire family has risen up against your servant, saying, 'Turn over the one who struck down his brother, so that we can execute him and avenge the death of his brother whom he killed. In so doing we will also destroy the heir.' They want to extinguish my remaining coal, leaving no one on the face of the earth to carry on the name of my husband."