The prophecy here is of Ammon, whom the King of Babylon also subdued as well as Jerusalem. The Lord hath been pleased to intersperse the history of Israel, here and there, with the account of other nations, by way of manifesting the sovereignty of His government, and to prove Himself to be King of Nations as well as King of Saints.
Ezekiel 21:28-32
28 And thou, son of man, prophesy and say, Thus saith the Lord GOD concerning the Ammonites, and concerning their reproach; even say thou, The sword, the sword is drawn: for the slaughter it is furbished, to consume because of the glittering:
29 Whiles they see vanity unto thee, whiles they divine a lie unto thee, to bring thee upon the necks of them that are slain, of the wicked, whose day is come, when their iniquity shall have an end.
30 Shall I cause it to return into his sheath? I will judge thee in the place where thou wast created, in the land of thy nativity.
31 And I will pour out mine indignation upon thee, I will blow against thee in the fire of my wrath, and deliver thee into the hand of brutishi men, and skilful to destroy.
32 Thou shalt be for fuel to the fire; thy blood shall be in the midst of the land; thou shalt be no more remembered: for I the LORD have spoken it.