And Absalom made Amasa captain of the host instead of Joab,
&c.] Who was along with David:
which Amasa [was] a man's son whose name [was] Ithra, an Israelite;
he is called Jether the Ishmaelite, ( 1 Chronicles 2:17 ) ; either because he was an Ishmaelite by birth, and being proselyted to the Jewish religion, was called an Israelite; or rather he was an Israelite by birth, and having sojourned in the land of Ishmael some time, was called an Ishmaelite, as Uriah the Hittite, and others; and when Amasa is called a "man's son", it means a great man, as Kimchi observes:
that went in to Abigail, the daughter of Nahash, sister to Zeruiah,
so that Joab and Amasa, the generals of David and Absalom, were own cousins, sisters' children, and David uncle to them both; for Abigail and Zeruiah were David's sisters, ( 1 Chronicles 2:16 ) ; children of Jesse, whose name is here called Nahash, having two names, or this was his surname; though others think Nahash is the name of a woman, the wife of Jesse, and that these two sisters had two mothers, but one father; it seems by this expression, "went in to", as if Amasa was not begotten in the conjugal state, but was illegitimate.