Tzitzit check - Meishiv Davar 1:2

In this teshuva written to the Chafetz Chaim, the Netziv takes issue with a psak written in the Mishna Berura (which was written by the Chafetz Chaim) where he writes that if one has a tallit which is pasul for some reason or another then he may not go outside on Shabbat with that tallit (in a place with no eiruv), and if he does he will be in violation of the prohibition of carrying on Shabbat (presumably he is considered to be carrying the strings).

The Netziv notes that the view of the Mishna Berura is against the overwhelming majority of Rishonim and Acharonim. According to Rashi, if one had techeilet that was not fit for the mitzva then he would violate the prohibition of carrying, but if one only has white strings they are not considered to be that important and thus there is no prohibition (remember, the Netziv lived before the revival of techeilet). According to Tosafot, there would only be a violation if one had a garment with three tzitzit made already and the fourth was missing.

The Netziv does point out that Rav Akiva Eiger leaves open the possibility that one could violate Shabbat with any form of psul in his tzitzit, but the Netziv counters that other than that possibility, there does not seem to be any major support for the position of the Mishna Berura. There also seems to be a view in the Rishonim that tzitzit should not be worn at all on Shabbat for this reason, but the Rosh rejects this as an unnecessary stringency.

Shatnez and Tzitzit - Meishiv Davar 1:1

In this first teshuva in this collection, the Netziv deals with a statement of the Magen Avraham who writes that one can put wool tzitzit on a linen tallit (in seeming violation of the laws of shatnez) if the corners of the tallit have leather patches on them. He initially raises two questions on this position. First, whether or not leather serves as a barrier vis-a-vis the laws of shatnez is actually a debate in the mishna in Kilayim. Second, there is a view that the tzitzit have to be made out of the same material as the corner from which they hang, and if that corner is made out of leather then there would be no obligation to have tzitzit there in the first place.

The Netziv then adduces a gemara in Yevamot which proves from a pasuk that shatnez is not a problem when it comes to tzitzit. However, he responds that the pasuk should not be needed if the leather patch can serve as an effective barrier. In other words, which is the true reason why this set-up should be permitted?

The Netziv spends some time on whether having or not having techeilet makes a difference (he says it does not), and whether this would be considered to be a situation of מצוה הבאה בעבירה. In the end, he concludes that there is no need to make a decree restricting one from making such a tallit, since if someone takes the time and effort to add the leather patches the chances are that we no longer have to worry about shatnez in that case.

Testing for Tay-Sachs - Igrot Moshe Even HaEzer 4:10

In 1973, Rabbi Moshe Tendler raised to his father-in-law the issue of testing for Tay-Sachs, a genetic disease found among Jews of Ashkenazic descent. The disease can only be contracted by a child whose parents were both carriers of the disease (even though it may not affect the parents at all), and the horrific impact is generally a very short life for the child. By the time of the question, reliable blood tests existed to help determine whether or not a person is a carrier for this disease, and Rav Moshe Feinstein was asked to rule on whether or not people should be tested before getting married.

Rav Moshe's initial response is to say that given the existence of such blood tests, avoiding having such a test would not only not be a lack of faith in God, but would actually be a case of closing one's eyes to something that he has the ability to know. Thus, Rav Moshe does encourage such blood tests to be taken by people who are contemplating marriage.

However, Rav Moshe does offer some caveats. First, he stresses that this should be a private process, to be revealed only when it is important with regard to a specific shidduch. Second, he notes that since people often get nervous about such issues and often make a bigger deal out of things than they should, therefore people should not be tested or even talked to about such testing until they are legitimately of an age when they may begin looking to get married.

Finally, it seems that there was a fund for Tay-Sachs research that included non-Jewish and non-religious doctors, which, among other things, encouraged the aborting of babies who were determined while in utero to have Tay-Sachs. Rav Moshe discouraged religious doctors from participating in this organization, but noted that if there were beneficial and halachically permissible aspects to this organization then they could join so long as they did not in any way lend their support to the aborting of babies.

The Missing Wife - Igrot Moshe Even HaEzer 4:2

A man from Kovno who emigrated to America in 1939 had planned to send for his wife as soon as was feasible. In 1940 he sent a coded message to her to join him, and she replied via telegram that she was on her way. After that, he never heard from her nor saw her again. In 1962, Rav Moshe ruled that it is a fair assumption that she was murdered along with so many others in the Holocaust, and that since the only reason that he could not remarry is the cherem of Rabbeinu Gershom that forbids polygamy (which thus ranks below a Rabbinic prohibition), he could remarry.

However, Rav Moshe does add that if the woman would show up at some point that he should write her a get immediately and pay her her ketubah.

The Princess Bride teshuva - Igrot Moshe Even HaEzer 4:1

In the movie "The Princess Bride," Wesley informs Buttercup that her marriage to Humperdink never happened since she never said "I do." Thus, there would be no problem marrying him (Wesley) since she was not actually married to another man.

A similar situation was presented to Rav Moshe Feinstein in 1977. A man had come to America from Russia and had been married before his emigration. However, it was common for weddings in Russia to be done without chuppah and kiddushin, and he had separated from his so-called-wife before he moved. Could he go ahead and marry another woman without having to worry about divorcing his previous wife?

Rav Moshe ruled that at a basic level he could marry another woman, since his original marriage was likely done without chuppah and kiddushin, and even for those who worry about civil marriage having some halachic import, even the civil marriage was merely an act of registering one's name with the local authorities (which could be undone by just as simple an act). Even further, it was common for people to be separated from their spouses by the government for one reason or another, usually for relocation purposes, and thus the entire enterprise of marriage was nearly meaningless.

However, while for marriage purposes for the man Rav Moshe had no major issues, he was concerned about the first wife resurfacing, claiming that their marriage was done with all proper halachic ceremonies, and being put into a possible situation of being an aguna. Thus, Rav Moshe suggested that the man draw up a get, or at least testify before witnesses that should the woman appear he will give her a get immediately without any complaints.

When is a mamzer not a mamzer? - Igrot Moshe Even HaEzer 4:23.1-2

I have already written up the last section of this teshuva, where Rav Moshe Feinstein used the behavior and character traits of the suspected mamzer as a final proof that he was not, in fact, a mamzer. In this summary I will focus on the bulk of the teshuva, where Rav Moshe tackles the essential halachic issues.


The question dealt with a woman who was civilly divorced in 1956 but only received her get in 1959. Later that year she married another man, and a few months later she bore a son. Clearly this son was not conceived after the second marriage. The new husband claimed that the child was his, and that the child had been concieved before the woman received her get. If that claim would hold, the child would be the product of an affair with an eishet ish, and thus would be a mamzer. The issues at hand focus on the trustworthiness of both the husband and the mother with regard to whether or not they can proclaim that their son is a mamzer.


The weightiest issue dealt with in the teshuva is that of yakir, the idea that the Torah recognizes a father's "recognition" of his children for halachic purposes. While we normally believe a father to say that a certain child is his, Rav Moshe notes that that only applies when he has raised the child and we have no reason to think otherwise. However, in this case it is clear that the child was concieved before he married the mother, and thus he does not have the right to declare his son a mamzer under the rubric of yakir. Rav Moshe claims that he does not even qualify as an eid echad to make such a claim.


However, Rambam seems to take the opposite view on this, claiming that a person can assert that someone is his firstborn for inheritance purposes, even if that son did not grow up with that father. Rav Moshe investigates this position and ultimately concludes that Rambam has two different takes on the law - one in the laws of inheritance and one in the laws of yuchsin (lineage). For inheritance purposes, Rambam would allow someone to make a claim about a child that he did not raise, while for lineage purposes a person cannot make such a claim with any degree of accepted credibility.

Taking that into account, Rav Moshe rules that we do not believe the new husband that he and the woman conceived the child before the divorce. This ruling is based on a variety of reason. One, we have no evidence that this woman was ever involved in a licentious relationship especially since for the three years since her civil divorce there was no indication that she was ever involved in a sexual affair. Two, even if there were witnesses that they were in seclusion with one another before her get was given, the gemara in Ketubot rules that we do not proclaim that a person is forbidden based on the knowledge that they had had yichud with someone. Three, if the only testimony that they had an affair is based on what the man says, then he would be incriminating himself, and we do not accept self-incriminating testimony.

With regard to any claims by the woman, we have less of a reason to believe her, since yakir only applies by the father and not the mother. As such, there is no halachically acceptable testimony that would establish that the child was conceived before the get was given, and thus Rav Moshe rules that he is not to be considered a mamzer.

When is a mamzer not a mamzer? - Igrot Moshe Even HaEzer 4:23.3

In this third and final section of a teshuva about a child who may or may not have been a mamzer, Rav Moshe Feinstein considers the implications of the fact that the potential mamzer was someone who had spent several years learning in Yeshiva and possessed fine character traits. Can those be used as evidence to help clear up confusion over whether or not he had been conceived in sin?

While Rav Moshe is hesitant to make such a move in the case of a mamzer, he invokes a different case as a parallel. He had been asked years earlier about someone who was a talmid chacham and a God-fearing Jew whose mother was known to have not kept the laws of niddah. As such, while this young man was not technically excluded from marrying a Jewish girl, he would be considered a בן נדה, which would be at least a blemish in the world of shidduchim. However, since there is a statement from Chazal that says that a בן נדה will possess the trait of brazenness, and this young man clearly did not fit that bill, then Rav Moshe surmised that perhaps it was possible that he was conceived when his mother was not a niddah.

How can this be the case if the mother never kept the laws of niddah? Rav Moshe suggested that perhaps there was a time when she entered a body of water that would qualify as a kosher mikveh, such as by swimming in the ocean, and even though she would not have had intention to enter it as a mikveh, and even though she would not have kept some of the other practices associated with the laws of niddah, such as הפסק טהרה or שבעה נקיים, nevertheless on a basic level she would have entered a mikveh and thus perhaps this young man was born soon after that event and thus he can be considered to not be a בן נדה for lineage purposes.

With regard to the actual question in this teshuva, which concerned someone who was potentially a mamzer, who is forbidden to marry a Jew, Rav Moshe feels that given the other potential reasons given in the other sections of the teshuva (to be written up soon), the fact that he is also a Torah scholar and a God fearing Jew can be used as additional support for the fact that he is not a mamzer.