Abishai, the son of Zeruiah, the brother of Joab is one of three sons of David’s sister Zeruiah (1 Chronicles 2:16; 2 Samuel 2:18). This would make him David’s nephew.1 Serving as one of David’s generals (2 Samuel 18:2),2 he and his brothers would later become a burden to David (see 2 Samuel 3:39; 2 Samuel 16:10; 2 Samuel 19:22).3
6 Then David said to Ahimelech the Hittite, and to Joab’s brother Abishai the son of Zeruiah, “Who will go down with me into the camp to Saul?” And Abishai said, “I will go down with you.”