Before we go hanging Moses' Ten Commandments in our courthouses, we best understand them. God did not tell Moses to go back to Egypt and make the worshipers of Osiris and Nut to obey these new rules. It would be like asking the average American to learn the rules of cricket. The people of the Exodus were the target audience for these laws because they had been baptized into faith at the Red Sea.

In the context of Deuteronomy chapter 30, anger is a strange god. From time to time, perhaps more often than we admit, our relationship with anger becomes religious. Anger goes from being a short defensive emotional state (without encouragement, the adrenal mechanism of anger only lasts about 90 seconds) to being a god that we worship. Every time someone burns our bacon, we have an opportunity to switch religions for a while. We bring an offering; our gift may sacrifice a friendship or destroy our own health. We repeat in public the litany of how we were wronged. When others agree with us, we experience the euphoria of holy communion. We commit ourselves to be regular attendees at the temple of anger. 

In the sermon on the mount, Jesus deals with anger as he makes the great Old Testament commandments relevant to daily life. Anger is intimately related to murder. Anger held past 90 seconds, takes on life of its own, and while we may not think of ourselves as capable of murder, we have only limited capabilities to keep ourselves from doing great harm. Our words may cut like a knife. Jesus stays practical when he talks about anger; you may find yourself in jail or worse.