The Forty-Fifth Prophecy of Jeremiah (see book comments for Jeremiah).
Concerning, &c. Supply the Ellipsis, from Jer_47:1.
Ammonites = sons of Ammon, north of Moab. When the tribes east of Jordan were carried away by Tiglath-pileser (2Ki_15:29), Ammon supplanted Gad. This is the sin dealt with here.