Amon and Moab

After Davening every Shabbos there is a Chinuch shiur followed by a kiddush. This week the group was learning about Amon and Moab and why even after conversion they are never allowed to marry a Jewish woman. This applies to all future generations and the prohibition is never lifted. The Chinuch explains that the reason for this is, that Amon and Moab refused to even sell food and water to the Jewish people when they passed near their territory before coming into the land of Israel. This behavior is counter to everything that the Jewish People and their ancestors stood for, Gemilat Chasodim. Our religion was built on helping and inviting people into our homes when they are in need. As a result of Amon and Moab's abhorrent behavior we reject them from entering our homes, even after conversion (it almost seems that Sodom influenced the children of Lot-my thought). The Chinuch continues that the females were not blamed or guilty of this behavior because it was not normal or modest in those days for woman to greet strangers into their homes. Therefore they are welcomed(after conversion) to marry Jewish males.
I find it ironic that Ruth (a convert from Moab)spent her days gathering from the fields of Boaz in order to sustain her mother-in-law,Naomi(a Jewess). It was this humility,love and concern for a fellow human being/Jew which was counter to the abhorrent behavior of her ancestors. As a result she eventually married Boaz. This marriage resulted in her building through her descendants,King David and the kingdom of Israel.