2 Samuel 17:25
And Absalom made Amasa captain of the host instead of Joab: which Amasa was a man's son, whose name was Ithra an Israelite, that went in to Abigail the daughter of Nahash, sister to Zeruiah Joab's mother.
Nave's Topical Index—AKJV

1 Chronicles 2:17
And Abigail bore Amasa: and the father of Amasa was Jether the Ishmeelite.
Nave's Topical Index—AKJV