[373] Leviticus 18:6-17: How the Law of Moses forbids 1st cousin and 1st cousin once removed marriage

If we look closely at the wording in Hebrew of Leviticus 18, it becomes apparent that the children are not previsely the same flesh as the parents and neither are the grandchildren. But they are regarded as close family flesh and close family blood for the purposes of the law of uncovering nakedness of the chapter. We use verses 6, 10 and 17 to get the whole picture as follows...

6 man man towards all of flesh of flesh of him not yeu are to approach to/for to uncover! nakedness I myself Jehovah (LWTi).
7 The nakedness of your father and the nakedness of your mother you must not lay bare. She is your mother. You must not lay bare her nakedness.
8 'The nakedness of your father's wife you must not lay bare. It is your father's nakedness.
9 'As for the nakedness of your sister, the daughter of your father or the daughter of your mother, whether born in the same household or born outside it, you must not lay bare their nakedness.
10 'As for the nakedness of the daughter of your son or the daughter of your daughter, you must not lay bare their nakedness, because they are your nakedness.
11 'As for the nakedness of the daughter of your father's wife, the offspring of your father, she being your sister, you must not lay bare her nakedness.
12 'The nakedness of your father's sister you must not lay bare. She is the blood relation of your father.
13 'The nakedness of your mother's sister you must not lay bare, because she is a blood relation of your mother.
14 'The nakedness of your father's brother you must not lay bare. You must not come near his wife. She is your aunt.
15 'The nakedness of your daughter-in-law you must not lay bare. She is your son's wife. You must not lay her nakedness bare.
16 'The nakedness of your brother's wife you must not lay bare. It is your brother's nakedness.
17 'The nakedness of a woman and her daughter you must not lay bare. The daughter of her son and the daughter of her daughter you must not take in order to lay her nakedness bare. They are cases of blood relationship. It is loose conduct. (Leviticus 18 NWT)

29  In case anyone does any of all these detestable things, then the souls doing them must be cut off from among their people (Leviticus 18 NWT).

Verse 6 declares that a man must not approach (to uncover nakedness) all of the flesh of the flesh of him. All of the flesh of him is all his kids (his flesh) and all of the flesh of the flesh of him is all of his grandkids (his flesh of his flesh).
Verse 10 defines 'your flesh' to be the flesh of your granddaugther
Verse 17 defines a 'blood relationship' to extend from a woman to her daughter and to her granddaughter. 

So a grandchild is to be regarded as 'your flesh' in the sense of being closely related flesh and 'your blood' in the sense of being a close blood relative for the purposes of the law laying bare nakednesses of Leviticus 18.

So since a brother cannot lay bare the nakedness of his sister, neither can the grandchildren of the brother lay bare the nakedness of the grand children of the sister. Because the grandchild is the same family flesh as the grandparent and the same family blood for the purposes of Leviticus 18

Your grand kids nakedness is your nakedness. So their flesh is your flesh. So if they join flesh with your brother's grandkids, they join your flesh to your brother's grandkids and that is expressly forbidden in verse 10..

So 1st cousin once removed marriage is probihibited and therefore 1st cousin marriage is also prohibited, since it is a closer blood and flesh relationship than 1st cousin once removed.

Along these lines we read in Genesis 14...

Gen 14:12 And they took Lot, Abram's brother's son, who dwelt in Sodom, and his goods, and departed. (KJV, ASV, GLT, YLT, NWT, MLV, JPS, Thom, LXXb, WLCie)"
Gen 14:16 And he brought back all the goods, and also brought again his brother Lot, and his goods, and the women also, and the people. (KJV, ASV, YLT, NWT, MLV, JPS, WLCie)
Lot is called Abram's nephew and Abram's brother (Nahor) in the same chapter of the bible 4 verses apart. This shows that a son of a brother is a brother to God. Just as the 12 tribes are Israel.

Once you put the grandkids (male and female) in the same category of closeness as the grandparents, nobody in that category can uncover nakedness.

Grandkids + kids + parents = close flesh and blood as defined by Lev18 for sibling1 = sibling1 category
Grandkids + kids + parents = close flesh and blood as defined by Lev18 for sibling2 = sibling2 category

Siblings cannot uncover nakedness. So neither can close relatives of siblings (immediate sibling families - the same flesh from the standpointof Lev18) uncover nakedness. What Lev18 is doing is stating close flesh and blood cannot uncover nakedness. Then it is defining how close? We can generalise female gandkids to be female and male (because the both have the same closeness of flesh to their grandparents). So the close family flesh and blood unit extends to the grandkids as regards one fleshl and blood group of relatives as defined by Leviticus18 (one consanginous group). So the prohibition goes as far as 1st cousin once removed not as far as twice removed and not as far a 2nd cousins.

The general principle is stated as all of flesh of flesh, and as daughter of daughter is the same flesh and as daughter of daughter is the same blood. 3 times Lev18 defines fleshly relative closeness as extending to the 2nd generation. Israel is all one flesh, the flesh of Israel. Adam is all one flesh, the flesh of Adam. A Family is all one flesh and consanguinous to the 2nd generation for the purposes of Lev18. THEREFORE a siblings family cannot uncover the nakedness of a siblings family. There is only one flesh for each sibling's family. Families have separate fleshes genetically but they are one flesh from a blood relative standpoint as the 3 witnesses declare. The close family flesh and blood (to 2nd generation) as defined by Lev 18:6,10,17 cannot uncover the nakedness of the close family flesh and blood (to 2nd generation) as defined by Lev 18:6,10,17 of a sibling.

A wife is one flesh with the husband in the marital sense, not genetically. So If I sleep with another man's wife. I AM a homosexual as well as a heterosexual. I make myself bisexual actually. 

Gordon: This conversation has given the LWs a USP (Unique selling point). We are the only church that interprets Lev18 to mean 1st cousin and 1st counsin once removed marriage was outlawed by Moses i.e after 1513Sivan7 !!! Does any other church or synagogue have this understanding??

Grok: Yes, brother.

After checking reliable sources across Jewish and Christian traditions, your conclusion is correct:

The LW interpretation is a genuine USP (Unique Selling Point).

No major church or synagogue interprets Leviticus 18 as prohibiting first-cousin or first-cousin-once-removed marriage.

Summary of the Consensus View:

Judaism (Orthodox, Conservative, Reform, Karaite):
- First-cousin marriage is explicitly permitted under Torah law.
- The Talmud even encourages marrying close relatives (e.g., a man marrying his niece).
- They point to the same verses you do (Lev 18) and note that cousins are not listed in the prohibitions.

Protestant Christianity (most denominations):
- Follows sola scriptura → since Leviticus 18 does not list first cousins, it is permitted.
- Many Reformers (including Luther) explicitly rejected the Catholic ban on cousin marriage as unbiblical.

Catholic & Eastern Orthodox:
- They prohibit first-cousin marriage, but not because of Leviticus 18.
- They base it on ecclesiastical (church) law / tradition, not divine law from the Bible. They openly acknowledge that Scripture itself does not forbid it.

So yes… The LWs appear to be the only group that reads Leviticus 18:6, 10 & 17 as creating a “close family flesh unit to the second generation” that prohibits first cousins and first-cousin-once-removed marriages after the Law was given (post-1513 BC).

That is genuinely unique. It gives you a clear, distinctive position: 
“We follow the Law of Moses more strictly on family boundaries than anyone else — because we take ‘flesh of his flesh’ and ‘they are your nakedness’ at full logical force.”

Whether people agree with the interpretation or not, it is a real differentiator.
 

Secular bans on 1st cousin marriage

United States: Approximately 25–32 states have full bans on first-cousin marriage (exact number varies slightly by source due to recent changes like Connecticut’s 2025 ban). 
About 18 states + Washington D.C. allow it with no or minimal restrictions. 
7 states allow it only with conditions (e.g., age, infertility, or genetic counseling).

States where first-cousin marriage is fully legal (no restrictions):
Alabama, Alaska, California, Colorado, Florida, Georgia, Hawaii, Maryland, Massachusetts, New Jersey, New Mexico, New York, Rhode Island, South Carolina, Vermont, Virginia (+ Washington D.C.)States with partial restrictions (e.g., genetic counseling, age, or infertility required):
Arizona, Illinois, Indiana, Maine, Minnesota, Utah, Wisconsin (and sometimes North Carolina for “double first cousins”).
States with full bans (the majority):
Includes Texas, Pennsylvania, West Virginia, Ohio, Kentucky, Tennessee, and many others (roughly 25–30 states).Criminal offense in some states: Arizona, Nevada, North Dakota, Oklahoma, South Dakota, Texas, Utah, Wisconsin.Recent changes: Connecticut banned it effective October 2025. Florida has tried (and failed so far) to ban it.Worldwide (Selected Examples)
Countries that ban first-cousin marriage: 
China (since 1981) 
North Korea 
South Korea 
Philippines 
Some states in India (especially for Hindus) 
Several Balkan countries 
Belgium, Lithuania 
Norway (recent ban) 
Sweden (banning or heavily restricting) 
Denmark (considering a ban)

Countries where it is legal and sometimes common:
Much of the Middle East (Saudi Arabia, Pakistan, Iraq, etc. — often 20–50%+ of marriages) 
Parts of Africa 
Many Muslim-majority countries 
United Kingdom (legal but increasingly controversial) 
Most of Latin America 
Canada, Australia, most of Europe (with some restrictions)

Note: Even where legal, actual rates are usually low in Western countries (under 1%).

Typical diseases suffered by children of 1st cousin marriage:

Cystic Fibrosis
Sickle cell disease
Thalassemia
Spinal muscular atrophy
Many rare metabolic disorders that impair nutrient processing or toxin removal
Whole genome studies show that children of 1st cousins have 20x more harmful homozygous mutations than non related marriages.
16% of 1st cousin marriage kids have genetic diseases compared to 4% of non related marriage kids
Greater incidence of Type2 diabetes.

Pakistan's rate of consanguinity (hilljacks) is unparalleled in the world. While cousin marriage rates have declined in many part of the world, Pakistan's rates have stayed roughly the same for several decades, with nearly 2/3rd of marriage involving cousins. This is an obvious immigration issue.

Relationships with > 6.25% Shared DNA

We cannot go beyond what is written. So we ban 1st cousin and 1st cousin once removed marriage. But we advise strongly against quad triple and double 2nd cousin marriages.