God demands justice for the deep humiliation suffered by the Israelites, holding neighboring nations accountable for their cruelty during a time of extreme crisis. God testifies about Himself [אבן עזרא] that He directly heard the mockery and contempt hurled by Ammon and Moab. These nations poured out disgrace and severe insults [מצודת ציון, שטיינזלץ]. However, their attacks took slightly different forms. While Moab directed their insults at the people of Israel themselves, the people of Ammon aimed their blasphemies specifically at the Torah and the sacredness of Israel, attacking what the nation held most holy [מלבי״ם].
The primary approach among commentators is that this cruelty took place during the bitter period of exile. As the Israelites were forced out of their land and marched through the territories of Ammon and Moab, these neighbors seized the opportunity to hurl harsh and degrading words at them [רד״ק, מצודת דוד]. Watching the Israelites crying, sighing, and shouting in pain on their journey into exile, Ammon and Moab cruelly mocked them. They taunted the exiles, claiming there was no reason to cry or suffer, since they were simply returning to the original homeland of their ancestors across the river [רש״י]. Alternatively, another perspective suggests that these insults were actually voiced much earlier, while the Israelites were still living securely in their own land, long before any exile occurred [אבן עזרא].
The aggression of Ammon and Moab extended beyond simple mockery, manifesting in either verbal arrogance or physical invasion. One approach understands their actions as expressions of extreme pride. The neighboring nations boasted [רש״י, שטיינזלץ], laughing and speaking harshly to humiliate the Israelites as they crossed their borders [מצודת דוד, רד״ק], or they arrogantly mocked the borders of the Land of Israel itself when they saw it lying in ruins [רד״ק]. A second approach explains that they took physical action. Rejoicing in Israel's downfall, Ammon and Moab invaded the ruined land. They seized territory to expand their own borders at the expense of Israel [מצודת דוד, מלבי״ם, שטיינזלץ]. This physical takeover was not just a land grab, but a deliberate attack on the holiness of the land and the faith of the Israelites [מלבי״ם].