The Ammonites, descendants of Lot through his younger daughter (Genesis 19:38), were a significant group in the biblical narrative, often depicted as adversaries of Israel. Their territory was located east of the Jordan River, in what is now modern-day Jordan. The Ammonites frequently engaged in conflicts with the Israelites, and their preparations for war are mentioned in several biblical accounts.

One notable instance of the Ammonites preparing for war is found in the context of their conflict with King David. In 2 Samuel 10, the Ammonites, feeling threatened by David's growing power, sought to strengthen their military position. They hired Aramean mercenaries to bolster their forces, indicating their serious intent to confront Israel. The biblical text states, "When the Ammonites realized that they had become a stench to David, they sent and hired Arameans from Beth-rehob and Zobah, twenty thousand foot soldiers, as well as the king of Maacah with a thousand men, and twelve thousand men from Tob" (2 Samuel 10:6).

The Ammonites' preparation for war was not only a military endeavor but also a spiritual and cultural one. They worshiped the god Milcom (also known as Molech), and their religious practices often included rituals that were abhorrent to the Israelites, such as child sacrifice (Leviticus 18:21). This idolatrous worship was a point of contention and a reason for divine judgment against them, as seen in the prophetic literature. The prophet Amos declared, "I will kindle a fire in the wall of Rabbah to consume its citadels amid war cries on the day of battle, amid a storm on the day of tempest" (Amos 1:14), highlighting the impending judgment on Ammon for their transgressions.

The Ammonites' hostility towards Israel is further illustrated in the book of Judges. During the time of Jephthah, the Ammonites waged war against Israel, claiming territorial rights over lands east of the Jordan. Jephthah, chosen as a leader to deliver Israel, responded to their aggression by recounting Israel's history and God's provision of the land. Despite his diplomatic efforts, the Ammonites persisted in their war preparations, leading to a significant battle where Jephthah ultimately defeated them (Judges 11:4-33).

Throughout the biblical narrative, the Ammonites' preparations for war serve as a backdrop for God's sovereignty and justice. Their repeated conflicts with Israel underscore the tension between the chosen people and the surrounding nations. The Ammonites' reliance on military alliances and idolatrous practices contrasts with Israel's call to trust in Yahweh. The biblical accounts of their war preparations reveal the broader spiritual and moral struggles that defined the ancient Near Eastern world and the unfolding of God's redemptive plan through Israel.