Jamieson, Fausset and Brown on Ezekiel 21:29

29. see vanity ... divine a lie--Ammon, too, had false diviners who flattered them with assurances of safety; the only result of which will be to "bring Ammon upon the necks," &c., that is, to add the Ammonites to the headless trunks of the slain of Judah, whose bad example Ammon followed, and "whose day" of visitation for their guilt "is come."

when their iniquity shall have an end--See on Eze 21:25.