וַיֹּ֤אמֶר אֲלֵיהֶם֙ מֹשֶׁ֔ה אִֽם־תַּעֲשׂ֖וּן אֶת־הַדָּבָ֣ר הַזֶּ֑ה אִם־תֵּחָֽלְצ֛וּ לִפְנֵ֥י יְהוָ֖ה לַמִּלְחָמָֽה׃
And Moses said unto them: ‘If ye will do this thing: if ye will arm yourselves to go before the LORD to the war,
Read halakhic rulings (Jewish law) on Numbers 32:20: and classical halakhic sources.