Nafka mina

Nafka mina (Aramaic: נפקא מינה, lit. "emerges from it" ) is a Talmudic phrase used in analytical debates. It is often used in the phrase "Mai nafka mina"? (מאי נפקא מינה), which asks, "What is the practical difference?"

Terminology

The question "mai nafka mina" is a way of testing the difference between two or more explanations for a given law, by investigating the different practical halachic rulings that would follow from each explanation. In other words, it means "so how do they differ in practice?"

It is contrasted with the question "be-mai peligei", which also means "how do they differ", but implies that the two views have the same practical consequences and that the difference is the intellectual process by which they are arrived at (for example, which Biblical verse is the relevant authority).

Example

Examples of a "nafka mina" abound, both in Jewish law as derived from the "Talmud", as well as in any situation that presents multiple rationales for a particular item.

To begin the "Shabbos" meals, "kiddush" is recited, followed by the eating of "challah". During "kiddush", the "challah" should be covered [Shlomo Ganzfried, "Kitzur Shulchan Aruch", 77:8] , which has led to a market for commercially available challah covers that are often beautifully decorated with embroidery or other designs. There are three reasons given for this practice:
#As a commemoration of the manna, which was covered by dew. [Shlomo Ganzfried, "Kitzur Shulchan Aruch", 77:8]
#As a mechanism to allow for the wine to be consumed prior to the bread. [Shulchan Aruch, Orach Chayim, "Hilchot Shabbos" 271:9 + associated Mishnah Berurah] In Jewish law, blessings are recited prior to the consumption of food or drink, and when faced with multiple food and drink items, there are laws stipulating which items should precede which others. Bread, as a staple food item, precedes all other foods and, in fact, the blessing recited over bread covers other food items (with some exceptions). If the bread was allowed to remain uncovered during the "kiddush", its preferential status would be belittled (known as "kadima", literally "first") when the wine is consumed first. [Shulchan Aruch, Orach Chayim, "Hilchot Shabbos" 271:9, associated Mishnah Berurah]
#As a display of honor for the "Shabbos" meals (יקרא דשבתא - lit. "preciousness of "Shabbos"). [Talmud Pesachim 100b, Tosafot "she'ein"] The notion of covering the "challah" is based on giving each course a sense of newness and fanfare by allowing it to "make an entrance." Each course is therefor brought out separately, rather than having them all at the table when the meal begins. Because the "challah" is supposed to be on the table during "kiddush", [Yehoshua Neuwirth, "Shemirat Shabbat Kehilchatah" 47:24] though, it is kept covered until it is ready to be served.

Now that the custom to cover the "challah" has been established together with its three reasons, one could ask what the "nafka mina" would be between the three reasons -- how would a difference in practice occur as a result of one rationale being dominant over another? Each of the following bullets represents a distinct "nafka mina":

*If the covering of the "challah" is because of "kadima", the "challah" may be uncovered immediately after "kiddush"; if because of the manna or honor, the "challah" should not be uncovered just because "kiddush" is over, but should remain covered until after "hamotzi" (the blessing over the "challah") is recited.
*"Kiddush" is not recited at the third meal. If covering the challah is because of the dew or honor, it should be covered at the third meal as well; if because of "kadima", there is no wine to disrupt the sequence of blessings and no cover is necessary.
*Because the dew enveloped the manna on both the top and bottom, the "challah" should be covered both on top as well as on the bottom; [Shulchan Aruch, Orach Chayim, "Hilchot Shabbos" 271:9, associated Mishnah Berurah] if because of "kadima" or honor, a simple napkin placed over the "challah" would do.
*If covering the "challah" is because of "kadima", only food items that precede wine in the sequence of blessings should be covered at the time of "kiddush" or remain off the table until after "kiddush". This would include only bread (which has a blessing of "hamotzei") and cake (which has a blessing of "mezonos"; if covering is because of the dew, only "challah" needs to be covered; if because of honor, even gefilte fish, cole slaw and other foods on the table should be covered (or brought to the table only when their respective course begins. [This is the view of Rabbi Hershel Schachter, rosh yeshiva at Yeshiva University.]
*If one makes "kiddush" over the "challah" (which is not ideal, but certainly permitted if one does not have wine), there is no issue of "kadima" and perhaps none of honor either, and no cover should be necessary; if because of dew, the "challah" should still be covered.

Reconciliation

*In practice, bread is not covered except on Shabbos and Jewish holidays with Shabbos-like work restrictions because bread eaten on a weekday is not tied to the manna. It is only on Shabbos, when two loaves are required as a commemoration of the double portion of manna that was given in the wilderness in honor of Shabbos, that we link our bread to the manna that was enveloped in dew.
*Many people do not cover the other foods on the table during "kiddush".
*The Mishnah Berurah asserts that when making "kiddush" on "challah", one should place one's hands on the challah cover until one reaches the actual blessing on the bread, uncover the "challah" and place one's hands on the "challah" itself for that blessing and then recover the "challah" and once again grab the "challah" through the cover for the concluding words of the "kiddush". [Shulchan Aruch, Orach Chayim, "Hilchot Shabbos" 271:9, associated Mishnah Berurah]
*Quoting the Aruch Hashulchan, Shemirat Shabbat Kehilchatah asserts that, while "it is not the custom to cover the "challah" during the third meal," some do indeed cover them to follow the other reasons. [Yehoshua Neuwirth, "Shemirat Shabbat Kehilchatah" 56:7]

References