Absalom had appointed Amasa over the army in place of Joab. Amasa was the son of Jether, an Ishmaelite who had married Abigail, the daughter of Nahash and sister of Zeruiah the mother of Joab.
David replied, “What does this have to do with you, you sons of Zeruiah? What right do you have to interfere? Should anyone be put to death in Israel today? Don’t I know that today I am king over Israel?”
Joab son of Zeruiah and David’s men went out and met them at the pool of Gibeon. One group sat down on one side of the pool and one group on the other side.
And today, though I am the anointed king, I am weak, and these sons of Zeruiah are too strong for me. May the Lord repay the evildoer according to his evil deeds!”
Abishai the brother of Joab was chief of the Three. He raised his spear against three hundred men, whom he killed, and so he became as famous as the Three.
David then asked Ahimelek the Hittite and Abishai son of Zeruiah, Joab’s brother, “Who will go down into the camp with me to Saul?” “I’ll go with you,” said Abishai.