There is a concept in the Talmud, known as dina demalchuta dina, which, when applicable, provides that the laws of the land are incorporated into halacha. These laws, once incorporated, must be obeyed, not only because they are the laws of the land but also because they become Jewish religious law. A prime example of the application of dina demalchuta dina is in the area of taxation and currency regulation.
Less clear, however, is whether the concept applies to the area of civil law such as the law of transfer of property. If the law of the land would apply, it would render the Jewish code of business law, now encoded in the Shulchan Aruch, Choshen Mishpat, redundant.
According to the Rambam, the law of the land is only imported into Jewish law in fiscal matters such as taxes and currency regulation, in which the government has special fiscal interest. Dina demalchuta dina does not apply, according to the Rambam, when it refers to transactions among citizens.
Other Rishonim, such as the Ramban, maintain that it does indeed apply to civil law in situations where the government insists that transactions are only valid if entered into in a legally prescribed way.
Although there is a difference of opinion about the application of dina demalchuta dina in connection with civil law, there is almost unanimous agreement that there is no such application to the Jewish law of inheritance. Accordingly, the Remah, in Shulchan Aruch Choshen Mishpat 369:11 writes that although dina demalchuta dina applies generally to civil law, it does not apply to the Jewish laws of inheritance.
Accordingly, a will made in accordance with the law of the land, in which the testator bequeaths his estate after his death to persons who are not recognized as heirs under Jewish law, such as a daughter in the presence of sons or a spouse in the presence of children, would be ineffective under Jewish law. There are two reasons for this. First, it contradicts the order of inheritance mandated by the Torah, which provides that neither a daughter nor a wife shares in the estate in the presence of sons or children respectively. Second, it purports to give away the property of the deceased after his death.
In Jewish law, a person cannot give away his property after his death because at that point he has no power of disposition over it and the laws of Jewish inheritance take over and decide for him how and to whom his estate shall be distributed.
Since dina demalchuta dina does not apply to the Jewish laws of inheritance, the only way to distribute one’s estate to persons who are not heirs under Jewish law is by means of a written “Will by way of gift of a healthy person,” which requires an overt act of transfer, a ma’aseh kinyan. A will that takes effect under the law of the land after the death of the testator without an act of transfer does not work under Jewish law.
There is, however, a notable exception to this opinion. Rabbi Moshe Feinstein writes that a testament made by a Jewish person while in good health according to the law of the land is valid in Jewish law, even though it was made without a ma’aseh kinyan.
“Although there is no such thing as a kinyan after death, and such a gift is not valid in Jewish law,” writes Rabbi Feinstein, “nevertheless, according to the law of the land a person can legally transfer, with effect after death, money or any other object. A testament of this kind, which will certainly be put into effect by the laws of the land, does not need a kinyan as one could not imagine a more effective kinyan than this. Hence, since a kinyan is not necessary, the legatees can uphold their right against those persons who are the proper heirs under Torah law, although there is no such thing in Jewish law as a gift after the death of the donor.”