Leviticus 18 contains a list of the types of sexual unions that are forbidden by the Lord. In Friday's study we read about the prohibition against a man sleeping with either his mother or a step-mother and the prohibition against sleeping with a full or half sibling. In today's study we look at several more forbidden unions between persons who are closely related either by blood or by marriage.
"Do not have sexual relations with your son's daughter or your daughter's daughter; that would dishonor you." (Leviticus 18:10) You'll note that these commandments are given to the men of Israel. People of that time lived in a patriarchal society where only men were the leaders of the family and the elders of the community. But all these rules can be applied to women as well. In verse 10 we find the Lord commanding the men of Israel to never have sexual relations with a granddaughter but it goes without saying that if this is sinful then a woman having sexual relations with a grandson is sinful as well.
It's safe to assume that the Lord is speaking of cases in which all parties involved are adults. When we hear the word "grandson" or "granddaughter" we tend to think of children but even in today's times when people don't live nearly as long as they lived in the early days of the Bible, most adults live to see their grandchildren grown and a lot of times they are blessed to see their great-grandchildren grow up too. For an adult to have sexual relations with a minor child is an abomination in the eyes of God, is morally reprehensible, and is illegal in most of the highly developed societies of the modern world. I don't think the Lord even has to bring up that subject in Leviticus 18 because the people already know what a sin this represents.
"Do not have sexual relations with the daughter of your father's wife, born to your father; she is your sister." (Leviticus 18:11) We touched on this subject yesterday in verse 9, which was worded slightly differently but which means the same thing. A man was not to consider a half sister as a suitable partner. Just because they were not full siblings didn't mean they could join together. Likewise, a woman could not consider a half brother as a partner.
"Do not have sexual relations with your father's sister; she is your father's close relative. Do not have sexual relations with your mother's sister, because she is your close relative. Do not dishonor your father's brother by approaching his wife to have sexual relations; she is your aunt." (Leviticus 18:12-14) A man couldn't have a physical relationship with his aunt, whether she was his aunt by blood or by marriage. By the same token, a woman couldn't have a physical relationship with her uncle, whether he was her uncle by blood or by marriage. If you ask me there's also an "ick factor" included in some of these relationships. Most people naturally recoil from the thought of sexual relationships with close relatives but in ancient times incest was common in many cultures. The Israelites have already seen the Egyptians engaging in incestuous marriages and relationships. They are going to see the tribes of Canaan doing the same things. The Israelites are not to live in the way these heathen idolaters live.
"Do not have sexual relations with your daughter-in-law. She is your son's wife; do not have relations with her." (Leviticus 18:15) A father-in-law and daughter-in-law are not related by blood. From a genetic standpoint there's no concern that their DNA is too closely matched to make it safe to produce offspring. But by the contract of marriage the two of them have become legally father and daughter. This is the only type of relationship they should have. In addition to that, a sexual relationship between them is adultery because the woman, at least, is married at the time. As if all this isn't enough reason to refrain from physical relations, such a thing represents a cruel betrayal. Imagine the pain a man would feel if his father behaved in such a way! It's bad enough when a man's wife is unfaithful to him; having her be unfaithful to him with his own father could be too much for some men to bear. This is another case where we can apply our verse to women and say that a woman is not to have sexual relations with her son-in-law.
"Do not have sexual relations with your brother's wife; that would dishonor your brother." (Leviticus 18:16) You can bet a thing like that certainly would make a brother feel dishonored. It's difficult enough for a husband to accept that his wife has slept with some other man, but when it's his own brother, the resulting anger and bitterness is capable of lasting not only through the lifetimes of the two brothers but could cause an ongoing feud between the two branches of the family. Again we can apply this verse to women, for a woman shouldn't even think of sleeping with her sister's husband.
"Do not have sexual relations with both a woman and her daughter. Do not have sexual relations with either her son's daughter or her daughter's daughter, they are her close relatives. This is wickedness." (Leviticus 18:17) A man could not have a wife or secondary wife or concubine and also sleep with that woman's daughter or with that woman's granddaughter.
In the Bible we never find the Lord giving His blessing to any sexual union except that which takes place between a husband and a wife. But when selecting a spouse, a person must take these laws of Leviticus 18 into account. Suppose a man divorces his wife and is single. Or suppose his wife dies and he is widowed. Can he marry his granddaughter? No. Can he break up his son's marriage and take his son's wife for himself? No. Can he seduce his brother's wife away from him and get married to her? No. Can he marry one of his aunts? No. If he finds himself in the position of having no wife and wanting to take a wife, he must choose a wife who is not closely related to him either by blood or by marriage.
We will likely need to take two more days to complete Leviticus 18 due to the amount of material contained in this chapter. We will see how and why these prohibitions are closely linked to the Lord's command not to engage in idolatry. We will be told why the Lord is going to uproot the tribes of Canaan to plant the tribes of Israel in their place, and the reason is closely related to the laws we're studying in this chapter.