וְדִבַּרְתָּ֣ אֵלָ֔יו וְשַׂמְתָּ֥ אֶת־הַדְּבָרִ֖ים בְּפִ֑יו וְאָנֹכִ֗י אֶֽהְיֶ֤ה עִם־פִּ֙יךָ֙ וְעִם־פִּ֔יהוּ וְהוֹרֵיתִ֣י אֶתְכֶ֔ם אֵ֖ת אֲשֶׁ֥ר תַּעֲשֽׂוּן׃
And thou shalt speak unto him, and put the words in his mouth; and I will be with thy mouth, and with his mouth, and will teach you what ye shall do.
Read halakhic rulings (Jewish law) on Exodus 4:15: and classical halakhic sources.