Ammonite: These nations were subjected for their impiety, wickedness, and enmity to Israel (Deuteronomy 23:4 and Deuteronomy 23:5), to peculiar disgrace; and on this account were not permitted to hold any office among the Israelites.
This did not, however, disqualify them from becoming proselytes; for Ruth, who was a Moabitess, was married to Boaz, and became one of the progenitors of our Lord.