From Sefer Likutei basar Likutei “And Moshe gathered all the congregation of B’nei Yisrael, and he said to them: 'This is what Hashem commanded: ‘Six days shall work be done, and on the seventh day holy for Hashem, a Shabbos rest.” What is the significance of Moshe gathering the people as opposed to all other commandments in the Torah, which were said to the B’nei Yisrael without specifically gathering them? The reason Moshe gathered them was to teach the commandments of er