בָּעֵ֣ת הַהִ֗יא אָמַ֤ר יְהוָה֙ אֶל־יְהוֹשֻׁ֔עַ עֲשֵׂ֥ה לְךָ֖ חַֽרְב֣וֹת צֻרִ֑ים וְשׁ֛וּב מֹ֥ל אֶת־בְּנֵֽי־יִשְׂרָאֵ֖ל שֵׁנִֽית׃
At that time the LORD said unto Joshua: ‘Make thee knives of flint, and circumcise again the children of Israel the second time.’
Read halakhic rulings (Jewish law) on Joshua 5:2: and classical halakhic sources.