He asked Zebah and Zalmunna, “What kind of men did you kill at Tabor?”“They were like you,” they said. “Each resembled the son of a king.” So he said, “They were my brothers, the sons of my mother! As the Lord lives, if you had let them live, I would not kill you.”
He went to his father’s house in Ophrah and killed his 70 brothers, the sons of Jerubbaal, on top of a large stone. But Jotham, the youngest son of Jerubbaal, survived, because he hid himself.
and now you have attacked my father’s house today, killed his 70 sons on top of a large stone, and made Abimelech, the son of his slave, king over the lords of Shechem ‘because he is your brother’—
so that the crime against the 70 sons of Jerubbaal might come to justice and their blood would be avenged on their brother Abimelech, who killed them, and on the lords of Shechem, who had helped him kill his brothers.
In this way, God turned back on Abimelech the evil that he had done against his father, by killing his 70 brothers.
2 Samuel 14:6
“Your servant had two sons. They were fighting in the field with no one to separate them, and one struck the other and killed him.
He told them, “This is what the Lord, the God of Israel, says, ‘Every man fasten his sword to his side; go back and forth through the camp from entrance to entrance, and each of you kill his brother, his friend, and his neighbor.’”
Then brother will betray brother to death, and a father his child. Children will rise up against parents and put them to death.