With Prime Minister Binyamin Netanyahu's trip to the US falling during the week of Yom Yerushalayim (Jerusalem Day), we Jews should remember that the Land of Israel is known as the Holy Land, Eretz HaKodesh, and Jerusalem as the Holy of Holies. To explain the latter term (in Hebrew, Kodesh HaKodashim), there is wisdom to be learned from our Hilchot Kashrut (the Torah laws of Kosher items).

The laws of mixtures (taaruvot) delineate what the law is when non-kosher items are mixed up with kosher ones.

There is wisdom to be learned from our Hilchot Kashrut.

What happens when such a mixture occurs, and then one item falls out of that first mixture and falls into another mixture? There exists a doubt (safek) as to the identity of any item in the first mixture. The corresponding doubt about any item in mixture number 2 is called a sfek sfeika, literally "a double doubt", created by shnei taaruvot, "two mixtures".

A double doubt is often (but not always) treated more leniently in Halacha than a simple safek, a single doubt. And a sfek sfeika can be created in other ways, too. For example, if a food item that is safek treifa (there is a doubt as to whether it possesses a particular physical defect) falls into a pot of food and gets mixed up in such a way that it cannot be identified and removed, there exists a sfek sfeika. This is a safek echad b'gufo, safek echad b'taaruvos - this is not a treifa (non-kosher) item that got mixed up in a pot, but a safek treifa; and if I pick out any item from this pot, there exists a doubt if the item is the safek treifa or one of the kosher items in the goulash. This type of sfek sfeika is treated leniently by Rabbeinu Tam (Talmud, Beitza 3b; Tosafot d'h vaacheirot baacheirot). The Shulchan Aruch, however, does not accept Rabbeinu Tam's lenient psak (decision) as Halacha (Yoreh Deah, 110, par. 9).

Rabbi Ahron Soloveichik explains that Rabbeinu Tam accepts the multiplicity of doubts as creating a likelihood of leniency. The first safek creates doubt as to whether the item has any issur (prohibition) at all, for perhaps it was not treifa, but kosher. When such an item is mixed up in a goulash, the second doubt is the "straw that breaks the camel's back" and legally allows us to eat any particular item in the mixture (but not all of them, for one is certainly the safek treifa). But the Shulchan Aruch holds that a safek echad b'gufo cannot be simply added arithmetically to a safek echad b'taaruvot to create a sfek sfeika, since the two doubts are not of the same type. The Shulchan Aruch's opinion is that to create a double doubt (and thereby to rule leniently), both doubts need to of the same type: either three mixtures (shalosh taaruvot; in paragraph 8, the Shulchan Aruch holds that two mixtures are not enough) or two safeik b'gufo. The Shach (in his long paragraph 63) explains this as b'guf echad uv'inyan echad, that both doubts must be of one kind, and then they can combine to create a sfek sfeika. Each such doubt strengthens the other and allows a lenient psak.

The term Holy of Holies, Kodesh HaKodashim, used in respect to Yerushalayim has the same grammatical form as sfek sfeika, and can be explained the same way.

Eretz Yisrael, the Land of Israel, is holy. The Torah says that the Nation of Israel is to provide the Holy Land a sabbatical (Shemita) year every seven years (Vayikra 25:4). After seven such cycles, "You shall consecrate the fiftieth year, and proclaim Liberty in the Land to all its inhabitants; it is the Jubilee Year." (verse 10) There is no requirement for all Jews to be living in the Land for Shemita to be in force, but there is such a requirement for the Jubilee year. The Aznayim L'Torah explains this requirement: the seventh year is holy and the Jews are holy. However, the multitude of seven cycles produces a Shabbat Shabbaton, a Sabbatical that is Kodesh Kodashim. This produces an extra degree of holiness in both the people of Israel and in the Land itself, because the two are of one kind. This is likened to the law that a Jew is holy and tefilin (phylacteries) are holy. A Jew may enter a bathroom carrying tefilin in their case, but a Jew wearing tefilin creates an extra degree of holiness, to such a degree that he may not desecrate that holiness by entering a bathroom.

The Aznayim L'Torah gives another practical result of this extra degree of holiness generated when the Nation of Israel dwells in the Land: opposition from the Dark Side. When Abraham and Isaac sought to live in Eretz Yisrael, there was no more than minor opposition from those who dwelt here. But the moment Jacob tried to return here

The moment Jacob tried to return here with his Twelve Tribes, the Satan himself mobilized all his forces.

with his Twelve Tribes, the Satan himself mobilized all his forces to prevent the Nation of Israel from establishing itself in its holy homeland, as a nation equal amongst the nations (Genesis 32:22-32; 33:1).

This is the opposition that we see today when the nations of the world try to separate us from our Land. But this Land is ours. It is only when the Holy People of Israel live in their Holy Land that this exponentially growing cycle of holiness creates a snowball effect. It is only Israel that is of a kind with the Land and the Land which is of a kind with Israel - so that the effects of both are additive, and each one catalyzes further and further growth of the other, in a creative round-robin of holiness.

And as the Mishnah says (Keilim, chapter 1, mishnayot 6-9): "There are ten levels of holiness: the Land of Israel is holier than all other lands... the walled city of Jerusalem is holier than all others." This is the unique situation which we, the people chosen for this Holy Land, and our Prime Minister should keep in mind as we celebrate Yom Yerushalayim, our Kodesh Kodashim.