Encyclopedia of Canon Law (Legislative Theology)

On the Impediments to Marriage (3)

Church Canons [9]
On the Impediments to Marriage (3)

This is the fourth article I present to you on the impediments to marriage. It is also the third concerning the prohibition of marriage with a wife’s sister and a brother’s wife.

The prohibition of marrying a wife’s sister and of marrying a brother’s wife
I will answer here the questions I have received on this topic, and any others that may arrive in the future.

Question 1
Was the prohibition of marrying a brother’s wife or a wife’s sister due to avoiding murder? Was it a civil prohibition ordered by kings, to prevent a brother from killing his brother to marry his wife, or a sister from poisoning her sister to marry her husband?

Answer
Scripture never mentioned that the reason for the prohibition was to avoid murder. It stated that the prohibition was because of forbidden kinship, to preserve chastity within the family. It is purely a religious reason.

A wife’s sister is considered a sister to the husband, and a husband’s brother is considered a brother to the wife, because marriage makes the two one. Thus, the relatives of one become relatives of the other. By affinity, the two families are united and become one family bound by kinship ties.

If a man views his brother’s wife as his sister, he cannot desire her or ever think of having her as his wife. But if he desires her, and wishes to marry her, and kills his brother to do so, this is the lowest state of family relations and human feelings. Religion, however, elevates the human spirit and prevents such desires at their root by setting laws for forbidden relationships. This was done by divine revelation in the first written law given by God through Moses the Prophet.

Scripture describes marriage with a brother’s wife as “uncleanness” (Leviticus 20:21): “He has uncovered his brother’s nakedness.” Likewise, in Leviticus 18:16: “You shall not uncover the nakedness of your brother’s wife; it is your brother’s nakedness.” Church canons prohibited such a marriage or such uncleanness. The same applies to marriage with a wife’s sister.

If some emperors forbade these marriages for civil reasons—such as to avoid crimes—that is their concern. But Scripture does not mention this. While civil laws may aim to prevent crime, divine revelation forbade lust itself, which leads to crime, and the Church canons followed this divine principle.

A man might travel and leave his wife and children under his brother’s care, being fully confident that his brother will not look upon his wife with lust, for she is like his sister. Likewise, if a married woman becomes ill and bedridden, she may ask her sister to live with her and care for her without ever thinking of desiring her sister’s husband. The husband, in turn, would view her as his sister. Divine law thus protects the purity and peace of the family.

But if a brother thought he could marry his brother’s wife after his death, or a sister thought she could marry her sister’s husband after her death, what would family relationships become? Scripture calls it “uncleanness.”

Question 2
Did some Christian kings truly permit marriage with a wife’s sister if it was proven that her death was not caused by her sister?

Answer
The permission of kings was civil, not ecclesiastical. A civil permit without an ecclesiastical one has no religious validity. We are not discussing civil marriage here; thus, the decrees of kings in this matter are irrelevant.

The Church canon clearly prohibits marriage with a wife’s sister.
In the previous issue, we presented ten points proving this. As for civil laws, some Christian countries allow divorce for reasons the Church does not accept, and even permit remarriage against canon law. Let us then leave aside such permissions and focus on the teaching of the faith.

Question 3
Does kinship end with the death of one spouse, thus removing the impediment to marrying a wife’s sister or a husband’s brother?

Answer
Kinship does not end with death. The evidence is clear:

Is it not forbidden for a man to marry his father’s wife (Leviticus 18:8; 20:11)? Does the father’s death end the kinship and make her permissible? For this very reason, Solomon ordered the death of his brother Adonijah when he sought to marry Abishag the Shunammite (1 Kings 2:21–24), even though David had never known her (1 Kings 1:4).

Likewise, is it not forbidden for a man to marry his mother-in-law (Leviticus 18:17)? Can anyone say the forbidden kinship ends with the daughter’s death? The same applies to marrying an uncle’s or aunt’s wife after their death (Leviticus 20:20), or marrying a son’s wife (Leviticus 18:15; 20:12). These forbidden relationships protect family chastity.

Question 4
Why was there an exception for marrying a brother’s wife if he died childless? (Deuteronomy 25)

Answer
Scripture gives the reason: to raise offspring for the deceased brother so that his name and inheritance might continue. This applied only to the tribal system of the Old Testament and has no place today.

Question 5
You mentioned that St. Basil the Great prohibited marriage with a wife’s sister in many of his canons. What reasons did he give?

Answer
Among his reasons: a sister should not ascend her sister’s marriage bed; and an aunt, who is like a mother, should never become a stepmother. I wish to translate for you St. Basil’s letter to Diodorus, Bishop of Tarsus, for it is full of profound meanings on this matter.

Question 6
Is a brother the best person to marry his deceased brother’s wife to care for his children?

Answer
If the deceased brother left children, it is forbidden for his brother to marry his widow. The Old Testament’s exception applied only when there were no children—to preserve the deceased’s lineage.

If a brother wishes to care for his brother’s children, he may do so without taking their mother as his wife. God forbade this marriage, even if it seemed practical, because He values family purity and the sanctity of marriage above all.

And I note: if kings once feared that a brother might kill his brother to take his wife, can such a man be trusted to care for his brother’s children? The righteous brother who truly cares for them is the one who does not ascend his brother’s bed.

Question 7
You mentioned that marriages causing confusion in kinship are forbidden. Does marriage with a wife’s sister or a brother’s wife cause such confusion?

Answer
Yes, these prohibited marriages lead to confusion:

1. A man marries his brother’s wife, who already has a son from his brother. If he has a daughter by her, that son and daughter would be siblings through the mother and cousins through their fathers.

2. A man marries his deceased wife’s sister and has children by her; his children from both sisters would be siblings through the father and cousins through the mothers.

Question 8
Is the prohibition of these marriages limited to a certain era?

Answer
No, these marriages are forbidden throughout all generations. The prohibition of marrying a brother’s wife was given in the Law of Moses fifteen centuries before Christ. It was reaffirmed in the apostolic age, the fourth century, and in the thirteenth century in the canons of Cyril ibn Laqlaq.

In the late 19th century, this prohibition appeared again in a personal status work by Archpriest Philotheos Ibrahim, teacher of our beloved Habib Girgis. He was a great theologian and the first modern instructor of theology in the seminary. His work prohibited marriage with a wife’s sister and all her relatives—her sister, mother, aunt, and so on.

This prohibition was also included in the 1938 regulation.
Even though that regulation was lenient regarding divorce (which we completely reject), its spirit of leniency did not extend to these forbidden marriages; it prohibited them, relying on Archpriest Philotheos Ibrahim’s canonical collection. The same is taught in the Theological Seminary today.

I recall that years ago, a priest permitted a man to marry his brother’s wife. Later, his conscience troubled him, and he brought the matter to court, which ruled the marriage invalid because it was between forbidden kin. I have the case number and judgment in my possession.

Here I conclude this discussion, yet I leave it open for any future questions. We stand beside the Church canons—and above all, the teachings of Scripture.