Reference for Numbers 8:20

וַיַּ֨עַשׂ מֹשֶׁ֧ה וְאַהֲרֹ֛ן וְכָל־עֲדַ֥ת בְּנֵי־יִשְׂרָאֵ֖ל לַלְוִיִּ֑ם כְּ֠כֹל אֲשֶׁר־צִוָּ֨ה יְהוָ֤ה אֶת־מֹשֶׁה֙ לַלְוִיִּ֔ם כֵּן־עָשׂ֥וּ לָהֶ֖ם בְּנֵ֥י יִשְׂרָאֵֽל׃

Thus did Moses, and Aaron, and all the congregation of the children of Israel, unto the Levites; according unto all that the LORD commanded Moses touching the Levites, so did the children of Israel unto them.