Abigail

Absalom had appointed Amasa over the army in place of Joab. Amasa was the son of a man named Ithra, the Ishmaelite who had married Abigail, the daughter of Nahash and sister of Zeruiah the mother of Joab.

Their sisters were Zeruiah and Abigail. And the three sons of Zeruiah were Abishai, Joab, and Asahel.

Abigail was the mother of Amasa, whose father was Jether the Ishmaelite.