Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
AMMONITES, or CHILDREN OF AM'MON, Gen 19:38, were the descendants of Ben-ammi, a son of Lot. He was born in the neighborhood of Zoar, but his posterity spread northwardly and occupied the mountain regions of Gilead, between the rivers Arnon and Jabbok. Originally their possessions were bounded north by the river Jabbok, west by Jordan, south by Arnon, and stretched eastwardly into Arabia.
The Amorites, under Sihon, their king, expelled them from the richest part of their possessions, which lay between the two rivers; but Moses recovered it from the Amorites and divided it between Reuben and Gad. The western boundary of the Ammonites then became a branch of the river Jabbok (on which their capital city, Rabbah or Rabbath-Ammon, stood), and the mountains of Gilead bounded them on the east, while the main stream of the Jabbok continued to be their northern boundary, and the land of Moab the southern. This last is intended by the kingdom of Ammon as used in the sacred history.
The children of Ammon were gross idolaters. Jud 10:6. Their chief idol was Molech, the same with Milcom, and their history is full of the judgments which their sins brought upon them, though they were spared, by God's express command, when Israel passed by them from Egypt, because Lot was their progenitor. Deut 2:19; 2 Chr 20:10. Three hundred years afterward the king of the Ammonites made war upon the Israelites, under the pretence that they had taken their land, Jud 11:13, and after a severe battle the Ammonites were routed with great slaughter.
In the beginning of Saul's reign, 1 Sam 11:1, the Ammonites, under Nahash, their king, attacked Jabesh-gilead, but proposed to spare the inhabitants provided they would all consent to lose the right eye. During the time allowed for their answer they collected a sufficient force to meet the Ammonites, and so completely routed them that two of them were not left together. Fifty or sixty years after this one of the kings of the Ammonites died, and David, who seems to have been under some obligation to him, sent a message of condolence to his son and successor.
This friendly act was not received kindly, and the messengers of David were grossly abused and insulted. See Hanun. Expecting that David would attempt to revenge the insult, they obtained large supplies of men from the Syrians; and when David heard of their preparation for war, he sent Joab, with a chosen troop from the army of Israel, to meet them. The result was fatal to the Ammonites. They and their allies were subdued, and fled.
Rabbah, their capital, and all the rest of their cities were afterward destroyed by the Israelites, the king's crown was taken from his head and put on David's head, and the people were reduced to a state of abject servitude. 2 Sam 12:26-31. In this condition they remained till the reign of Jehoshaphat, when they united with the Moabites and others and made war upon Judah, and were miraculously cut off. 2 Chr 20. Jotham fought and prevailed against them, and made them tributary for several years.
Many Jews sought refuge among them in the time of the Captivity, but they do not seem to have decreased their hostile feeling. The most dreadful judgments were threatened against them and their chief city because they seized and occupied a part of the territory of Israel, Jer 49:1-6, and again because they insolently triumphed over the Israelites in the days of their captivity, Eze 25:2-7, 1 Kgs 16:10; and every threat was executed to the very uttermost in due time, as profane history abundantly attests. " They were a cruel, remorseless, nomadic people.
To their god Molech they offered human sacrifices. See Molech. Where their capital once stood is now the village of Amman, 20 miles south-east of the modern town of ce-Salt.