1) THE DIFFERENCE BETWEEN A "PRAT KLAL U'FRAT" AND A "RIBUY U'MI'UT"
QUESTION: The Gemara says that the Tana'im who use the approach of "Ribuy u'Mi'ut" and the Tana'im who use the approach of "Klal u'Frat" agree that when the verse mentions a limiting phrase, then a general phrase, and then another limiting phrase, the verse is expounded as a "Prat Klal u'Frat," which teaches that all items that are similar to the Prat are included in the law of the verse (and all items that are not similar to the Prat are excluded) -- "Marbeh k'Ein ha'Prat." According to the Tana'im who use the approach of "Ribuy u'Mi'ut," when the verse mentions only a general phrase and then a limiting phrase, the verse is expounded as a "Ribuy u'Mi'ut," which also teaches that all items that are similar to the Prat are included in the law of the verse -- "Marbeh k'Ein ha'Prat."
According to the Tana'im who expound "Ribuy u'Mi'ut," in every case of a "Prat Klal u'Frat" why does the Torah need to mention the first limiting phrase? It should leave out the first Prat, and the verse still would teach "Marbeh k'Ein ha'Prat" through a "Ribuy u'Mi'ut," a general phrase followed by a limiting phrase! (GA'ON AVRAHAM cited by the ARZEI HA'LEVANON, fn. 53*)
TOSFOS (35b, DH Ika) asks a similar question with regard a "Ribuy Mi'ut u'Ribuy," a Limud which teaches that all objects are included in the law of the verse except for one object. Tosfos asks why the Torah needs to write the first Ribuy in such a case, when it could write just the second and third phrases (the Mi'ut and the Ribuy). The Limud of "Mi'ut v'Ribuy" would also teach that everything is included except for one object! Tosfos answers that indeed the first Ribuy is not necessary; the Torah adds it only because it is the style of the verse to open with a Ribuy. Hence, the Limud of "Ribuy Mi'ut u'Ribuy" and the Limud of "Mi'ut v'Ribuy" are actually the same Limud.
The answer of Tosfos does not suffice to explain why the first Prat is ever needed in the case of a "Prat Klal u'Frat." If the first limiting phrase of the "Prat Klal u'Frat" is included in the verse merely because that is the style of the verse ("Orchei d'Kra"), the following two terms are actually being expounded as a "Ribuy u'Mi'ut" and not as a "Klal u'Frat." Accordingly, the Gemara should not call it a "Prat Klal u'Frat" and state that all Tana'im agree that it is not viewed as a "Mi'ut Ribuy u'Mi'ut," but rather the Gemara should call it a "Mi'ut Ribuy u'Mi'ut" in which the first Mi'ut is disregarded! It must be the Limud teaches something different when it is viewed as a "Prat Klal u'Frat" than when it is viewed as a "Ribuy u'Mi'ut." What is that difference?
ANSWER: A "Ribuy u'Mi'ut" teaches that any object that is similar to the Prat is included in the law of the verse ("Marbeh k'Ein ha'Prat"), even if the object in question is similar to the Prat in just one respect ("Tzad Echad"). In contrast, when the verse is expounded as a "Prat Klal u'Frat," it teaches that only an object that is similar to the Prat in two respects is included in the law of the verse (like the Gemara mentions on 35b).

35b----------------------------------------35b

2) "HETER MITZTAREF L'ISUR"
QUESTION: The Gemara introduces the concept of "Heter Mitztaref l'Isur." One is punished for transgressing the Torah's commandment against eating a forbidden item only when he eats an item of a minimum size. "Heter Mitztaref l'Isur" teaches that the minimum size may be comprised of the forbidden item combined with a permitted item. Rebbi Avahu in the name of Rebbi Yochanan states that only with regard to the prohibitions of Nezirus does "Heter Mitztaref l'Isur" apply, but not to any other Isur in the Torah. An example of "Heter Mitztaref l'Isur" is when a Nazir dips his bread (which is permitted) into wine (which is forbidden) and eats the mixture, and together the bread and the wine have a total volume of a k'Zayis. Even though the wine alone does not comprise the minimum Shi'ur of a k'Zayis, the Nazir is liable since the total Shi'ur of the mixture is a k'Zayis (Tosfos, DH Chutz mi'Nazir).
A different principle, "Ta'am k'Ikar," teaches that when an Isur is absorbed in a permissible food item, the entire item becomes forbidden if the taste of the Isur is palpable. When a Nazir dips his bread into wine, the bread should become forbidden because of "Ta'am k'Ikar," since the taste of the forbidden wine is spread (and noticeable) throughout the bread. Why, then, is the concept of "Heter Mitztaref l'Isur" necessary? The permissible item (the bread) would be forbidden even without the Halachah of "Heter Mitztaref l'Isur," because of "Ta'am k'Ikar."
One cannot answer that when the bread is dipped into wine the taste of the wine is not noticeable in the bread, because in such a case the wine would be Batel (nullified) completely and "Heter Mitztaref l'Isur" would not apply. As the RAMBAN (in Milchamos to Pesachim 43b) points out, this is clear from the Gemara in Pesachim (30a) which states that when even a tiny amount of Chametz is mixed with another food item ("Ta'aroves Chametz"), the mixture is prohibited mid'Rabanan. If a tiny amount of Isur in Heter is not Batel and "Heter Mitztaref l'Isur" applies, then the mixture with Chametz should be Asur mid'Oraisa because of "Heter Mitztaref l'Isur" -- the permissible food should add to the fractional Shi'ur of the Chametz to make a k'Zayis. It must be that mid'Oraisa the small amount of Chametz in the mixture is Batel, and when an Isur is Batel the concept of "Heter Mitztaref l'Isur" does not apply. On the other hand, when the Isur is not Batel (that is, the taste of the Isur is palpable in the mixture), the mixture is Asur because of "Ta'am k'Ikar." What is the need for the concept of "Heter Mitztaref l'Isur"?
ANSWERS:
(a) RASHI in Pesachim (44b, DH mi'Pas) understands that when a forbidden item gives its taste to a permitted item, the taste of the Isur in the permitted item renders the entire permitted item an object of Isur. (This is known as "Chatichah Na'aseh Neveilah" -- the forbidden taste of Neveilah in a permitted piece of meat renders the entire piece of meat forbidden as if it were a piece of Neveilah. According to Rashi, the concept of "Chatichah Na'aseh Neveilah" is mid'Oraisa and is part of the principle of "Ta'am k'Ikar." See Chulin 100a.)
Accordingly, Rashi concludes that the concept of "Heter Mitztaref l'Isur" is necessary in a case in which part of the Heter did not absorb the taste of the Isur. According to the rule of "Ta'am k'Ikar," that part of the Heter is not included in the Shi'ur of the Isur. According to the rule of "Heter Mitztaref l'Isur," however, that part of Heter does count towards the Shi'ur of Isur and it is added to the part of Heter which did absorb the taste of the Isur. Therefore, when a Nazir dips his bread into wine, the part of the bread which does not absorb any wine joins with ("Mitztaref") the part of the bread which did absorb wine. In such a case, "Ta'am k'Ikar" does not apply to the entire k'Zayis because the taste is not present throughout all of the k'Zayis, but only in less than a k'Zayis of the bread. The reason of "Heter Mitztaref l'Isur," however, does apply.
For this reason, Rashi in Pesachim (43b, DH Ein Heter) writes that even when one takes two separate items (one of Isur and one of Heter) and places them into his mouth at the same time, he is liable because of "Heter Mitztaref l'Isur."
(b) The RAMBAN (Milchamos, loc. cit.) writes that "Ta'am k'Ikar" applies even to a mixture in which the Isur is not "b'Ein" -- where there are no physical pieces of Isur evident in the mixture, but only the taste of the Isur is absorbed into the food (such as water in which grapes were soaked and which absorbed their taste). If the taste of the Isur in the Heter is equivalent to the amount of taste conveyed by a k'Zayis of Isur which is ground into the Heter, "Ta'am k'Ikar" applies (but not "Heter Mitztaref l'Isur"). However, only when there is a k'Zayis of "Ta'am" within "Kedei Achilas Pras" (the time it takes to eat half a loaf of bread) is the person liable for Malkus. This is the application of the principle of "Ta'am k'Ikar."
The principle of "Heter Mitztaref l'Isur," on the other hand, applies when the Isur itself is visibly absorbed in the Heter (such as wine absorbed in a piece of bread). The law of "Heter Mitztaref l'Isur" teaches that in such a case, even though there is not enough of the Isur mixed with the Heter such that one who eats the mixture will eat a k'Zayis within "Kedei Achilas Pras," one still will be liable. (This also appears to be the opinion of TOSFOS and most Rishonim. They do not agree with Rashi that "Chatichah Na'aseh Neveilah" is an inherent part of the principle of "Ta'am k'Ikar.")

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