Ithra

(excellence), an Israelite, (2 Samuel 17:25) or Ishmaelite, (1 Chronicles 2:17) the father of Amasa by Abigail, David’s sister. (B.C. before 1023.)

ith'-ra (yithra', "abundance"): The father of Amasa, commanding general in the rebel army of Absalom. It seems that his mother was Abigail, a sister or half-sister of King David (1Ch 2:17). She is called the sister of Zeruiah, Joab's mother (2Sa 17:25). In this same passage Ithra is called an "Israelite," but in 1Ch 2:17; 1Ki 2:5,32, we read: "Jether the Ishmaelite."