Moses starts his preamble in chapter 33 with God coming down on Sinai to give the people the law, rather than with God’s calling of the patriarchs or with Jacob’s twelve sons. There’s a very good reason for that. His blessing upon the people is a blessing upon the nation. In a sense, the nation began at Sinai. It did begin with God calling a people to Himself, beginning with Abraham, and then their multiplying in Egypt and coming out as a great people. But they were formed into a nation at Sinai because they were given the law and had been instructed in the right way of approaching God.