When God brought the people of Israel out of Egypt with “a mighty hand and an outstretched arm,” that deliverance from slavery to freedom became a central orienting event in the minds and hearts of God’s people. The Exodus was celebrated and remembered every year at Passover, and it became the focal point of their identity as a people. They were the people whom God had redeemed from slavery, who had experienced the mighty testimony of his judgments against their captors and his miracles of provision on their behalf, and who waited in hope for a Messiah who would bring an even greater deliverance, of which this one was just a forerunner.
God’s purpose in delivering them was much greater than just delivering them “out” of something, namely oppression and slavery. His purpose was also to bring them “into” something—a life of holiness by which they would truly reflect his image in the world. In order to instruct and form this newly redeemed people into a faithful covenant people, God gave them the revelation of the Law at Mount Sinai. Through the Law, God was demonstrating his own holiness and covenantal love, and also revealing to the people of Israel how they were to live and act as his covenant people. You can think of the Law as providing a tangible picture, through words, of what life is meant to look like when lived in proper obedience to our loving heavenly Father.