Did you know that Leviticus 20:21 was partly responsible for starting the protestant reformation in England.
It is often said that Henry VIII needed to separate from the Church of Rome so that he could divorce Catherine of Aragon. It is therefore said that the English reformation had its roots in political concerns, rather than religious ones. That is true as far as it goes. It is also true that there were theological issues swirling on the continent, that meant many English churchmen were more than ready for a break with Rome, and Henry VIII's political manoeuvres just set the scene for what would probably have happened anyway.
However let's pause for a moment to ask why Henry VIII wanted to divorce Queen Catherine. None of the children she had born to him survived childhood. There was therefore a growing prospect that Henry's daughter, Mary, would inherit the throne. Henry was desperate to avoid this.
Henry VIII was not the oldest son of his predecessor, Henry VII. Henry VIII had an older brother, Arthur, who died at the age of 15. That left Henry VIII to inherit the throne. However he took more than just the throne from his dead brother. Before Arthur died, he was married to one Catherine of Aragon. The death of Prince Arthur, the Prince of Wales, left Catherine free to remarry in the eyes of the law; Henry VIII did nothing wrong. However he was haunted by Leviticus 20:21 - "If a man takes his brother's wife, it is impurity. He has uncovered his brother's nakedness; they shall be childless." Clearly that verse is not saying that a man should not marry his brother's wife while his brother is still alive; that would be adultery, which is condemned elsewhere. Leviticus 20:21 says that a man should not marry his brother's wife after the death of his brother. So Henry began to be increasingly concerned that his inability to produce an heir through Catherine was because Catherine had been formerly married to Arthur. "They shall be childless".
That's a little piece of history for you.
More important is that we don't miss what goes on further down that chapter. It gives an important key as to why Leviticus has all the archaic laws it does - not eating certain types of meat, and so on. Verse 24 is the key to the chapter. "I am the Lord your God who has separated you form the peoples." God has chosen the people of Israel to be his special people, separate from the surrounding nations. They are to be his.
This cashes out morally in the verse before that, verse 23: The nations who lived in Canaan before them did many things that displeased God. Archaeology has uncovered such practices as child sacrifice. The people of Israel are not to be like that. Then verse 25, the verse after the key verse 24, cashes it out ritually. They are to separate clean from unclean animals, and not make themselves unclean by what they eat or touch.
The food laws, and the laws on defiling contact, were not arbitrary. They were there as a visual aid to remind the people that they are to be distinctive. They are not just to copy the people around them. They are not free to eat or touch anything they fancy. They are the Lord's people, called to be clean for him. The dietary restrictions were a daily reminder of this.
We, today, can eat any meat we wish. Jesus "declared all foods clean" in Mark 7. But we still need reminding that God has called us to be his own. We are not to pick up our moral standards from the peoples around us; we are to ask what pleases our Lord Jesus, and to live exclusively for him. The food laws, that we no longer need to obey, can still stir us to live for the Lord Jesus who has rescued us.