Deuteronomy 6:21 - Ellicott's Commentary On The Whole Bible

The Lord brought us out of Egypt. — The simple explanation of the obligations of the Law given in these verses is based upon the message of Jehovah to Israel from Sinai. in Exodus 19:3-6 : “Ye have seen what I did unto the Egyptians, and how Ì bare you on eagles’ wings, and brought you unto myself. Now therefore, if ye will obey my voice indeed, and keep my covenant, then ye shall be a peculiar treasure unto me.” The keeping of the Law of Jehovah by Israel as a nation in the land that He gave them was the final cause of their national existence. This fundamental fact must never be forgotten. This alone would justify what had been done to Egypt. Hence the neglect of the Law must inevitably bring down the Divine vengeance.