בַּיּ֣וֹם הַה֗וּא נִקְרָ֛א בְּסֵ֥פֶר מֹשֶׁ֖ה בְּאָזְנֵ֣י הָעָ֑ם וְנִמְצָא֙ כָּת֣וּב בּ֔וֹ אֲ֠שֶׁר לֹא־יָב֨וֹא עַמֹּנִ֧י וּמֹאָבִ֛י בִּקְהַ֥ל הָאֱלֹהִ֖ים עַד־עוֹלָֽם׃
On that day they read in the book of Moses in the hearing of the people; and therein was found written, that an Ammonite and a Moabite should not enter into the assembly of God for ever;
Read halakhic rulings (Jewish law) on Nehemiah 13:1: and classical halakhic sources.