Chapter 4 is one of the great sermons of the Bible. This sermon finds its focus and heart in verse 29, “But if . . . you seek the Lord your God, you will find him if you seek him with all your heart and with all your soul.” Years later the prophet Jeremiah will appeal to this text in his letter to the Hebrew exiles in Babylonia (Jer. 29:13).

Based on the preceding historical review, Moses here transitions to exhorting Israel as he calls them to follow God’s instruction. The reason or purpose for observing God’s guidance in his laws is “so that you may live” (4:1). Few phrases are repeated more frequently in this book (e.g., 5:33; 6:2; 11:21; 25:15; 30:6), climaxing in 30:15–20 as a call to life as God means it to be lived. This life is found only by belief and trust in the word of God, w…