1"You are the sons of the LORD your God; you shall not cut yourselves nor shave your forehead for the sake of the dead.
2"For you are a holy people to the LORD your God, and the LORD has chosen you to be a people for His own possession out of all the peoples who are on the face of the earth.
3"You shall not eat any detestable thing.
Every aspect of life in the Israelite camp was hemmed in by rules. There was a lot of you can't do this, but you have to do that when it came to eating, mourning a death, legal issues, medical issues, where their families could camp, how to worship, how to wash and on and on. In some ways it made life easier because they didn't have to think very hard about how to do the daily stuff of life. They just had to know and follow the rules. God made the rules very clear as you can see in this chapter and throughout the Old Testament.
There was a radical change from the Old Testament to the New Testament concerning rules. They were transferred from the pages of a book onto the hearts of God's people. Instead of being regulated from the outside book of rules, God's people are now to be regulated by the Spirit inside them. Many of the rules that kept the Israelites separate from other people groups were discarded in the changeover. God wanted the Jews to be separate because it was through them He gave His Word and to whom He revealed Himself until He brought Jesus into the world. They protected His Word and provided the means by which He carried out his plan of salvation.
Now, God's people with their new hearts are not to live separate any more. They are to live among all the people of the earth to spread the good news of Jesus who saves and will guide their lives, not by rules, but by the Spirit in them. However, because people still like rules, it is easy for believers to forget about the Spirit and to revert back to rules. It is a daily challenge for God's people to put off the old ways of living by rules and to put on God's Spirit to lead and empower.