1) COMBINING "ORLAH" AND "KIL'AYIM"
QUESTION: The Mishnah states that Orlah and Kil'ayim combine to form a k'Zayis of Isur.
Earlier (17b), the Gemara cites a Beraisa which derives from a verse that Pigul and Nosar combine to make a Shi'ur of Isur. Without such a verse, there would be no source that the two Isurim combine. Why does the Mishnah here state that Orlah and Kil'ayim combine if there is no specific verse that teaches that they combine?
ANSWERS:
(a) The RASH in Orlah (2:1) and the RAMBAM (Hilchos Ma'achalos Asuros 15:14) explain that the Mishnah does not mean that the two Isurim combine to form a k'Zayis of Isur in order to obligate one who eats the combination to receive Malkus. Rather, the Mishnah is discussing the law of Bitul. If one part of Orlah and one part of Kil'ayim fall into 199 parts of Heter, the Halachah does not state that each Isur combines with the Heter to annul the other Isur; the Halachah does not view it as though there is one part Orlah or one part Kil'ayim in 200 parts of Heter and the Isur thus becomes Batel. Rather, the Halachah states that there are two parts of Isur in 199 parts of Heter, and thus they are not Batel.
(b) RASHI (DH ha'Orlah) says that the combination of Orlah with Kil'ayim mentioned in the Mishnah here is similar to the combination of Pigul and Nosar mentioned in the Mishnah earlier. Rashi clearly understands that they combine to form a Shi'ur of Isur. How can they combine, if there is no source in the verse?
The MAHARI BEN MALKI-TZEDEK (Orlah 2:1) explains that the Mishnah here follows the view of Rebbi Meir, who rules in Avodah Zarah (66a) that all Isurim combine to form a Shi'ur of Isur because of the prohibition of "Lo Sochal Kol To'evah" -- "You shall not eat any abominable thing" (Devarim 14:3).
2) "MIPNEI SHE'HEN RE'UYIN LI'TAMEI B'MOSHAV"
OPINIONS: Rebbi Shimon states that the reason why various types of materials combine to make a Shi'ur of Tum'ah is that "they are fit to become Tamei with Tum'as Moshav." What is the reasoning behind this statement?
(a) RASHI here and in Shabbos (76a) explains that various materials may be combined to create a Shi'ur of Tum'ah since they are sometimes sewn together into one piece, such as when a person makes a quilted donkey-saddle.
Rashi's logic apparently is as follows. It is obvious that there is a sufficient amount of material to be Mekabel Tum'ah, since there is even enough in the combination to satisfy the largest Shi'ur involved. However, there is a doubt about whether different materials can be combined altogether; perhaps we should assume that the materials will soon be removed from each other, and, consequently, we should view them as already being separate entities.
Therefore, in order to rule that materials combine, it first must be proven that the combination is indeed tolerated. Since people sew together different materials to make a donkey-saddle, the mixture may be viewed as a lasting combination and thus the various amounts combine to create a Shi'ur of Tum'ah.
(b) The Mishnah earlier (17a) teaches that two different objects that become Tamei or spread Tum'ah with the same minimum Shi'ur (such as a k'Zayis) and with the same degree of Tum'ah combine to make a Shi'ur of Tum'ah. Since, in one case, the Shi'ur needed to cause Tum'ah with all of the materials mentioned in the Mishnah is the same, they may be combined to make a Shi'ur of Tum'ah.
It what case is their Shi'ur for causing Tum'ah the same? The case is where they were specifically prepared to be used for a donkey-saddle, in which case they are all Metamei when they are one Tefach long by one Tefach wide (RASHI to Sukah 17b, DH Ho'il; TOSFOS to Shabbos 76a, DH Ho'il). (See also Insights to Shabbos 76:1.)

18b----------------------------------------18b

3) STEALING FROM THE BEIS HA'MIKDASH
QUESTION: The Gemara (18a) teaches that the concept of Me'ilah in the verse, "Nefesh Ki Sim'ol Ma'al" -- "A person who commits Me'ilah and sins unintentionally against the Kodshim of Hash-m" (Vayikra 5:15), means "Shinuy," a change. As TOSFOS (DH Ein) and the SHITAH MEKUBETZES (#33) explain, when a person commits Me'ilah, he changes the sanctified object by removing it from the domain of Hekdesh when he uses it for his personal benefit.
The Gemara supports this meaning of "Me'ilah" from the verse, "u'Ma'alah Vo Ma'al" (Bamidbar 5:12), which refers to an unfaithful wife who "changes" from the domain of her husband to the domain of an adulterer (see Tosfos).
As RAV CHAIM SOLOVEITCHIK notes (Hilchos Me'ilah 8:1; see Insights to Me'ilah 13:3), it is evident from the Gemara here that the nature of the prohibition of Me'ilah is a prohibition against stealing an object from Hekdesh ("changing" the object from the domain of Hekdesh to the domain of someone else).
Rav Chaim cites three other proofs to this concept:
1. His first proof is the Mishnah (18a) that states that one is Chayav for Me'ilah when he derives benefit from a Perutah's worth of Hekdesh. A Perutah, as the smallest form of currency, represents the smallest amount that can be considered property of value ("Mamon"). In contrast, prohibitions that involve eating forbidden foods are measured by a k'Zayis. This shows that the Isur of Me'ilah is an Isur of gaining monetary benefit from Hekdesh.
2. The Gemara here states that even if one derived a Perutah's worth of benefit from Hekdesh over a very long period of time (such as by eating half a Perutah's worth on one day, and half a Perutah's worth many days later), he still transgresses the Isur of Me'ilah. In contrast, prohibitions that involve eating forbidden foods are measured by a k'Zayis eaten within a specific time period, "Kedei Achilas Peras." Accordingly, the Isur of Me'ilah is similar to the Isur of stealing, which is also determined by the value of a Perutah and has no time limit.
3. The Gemara states that one's consumption of Hekdesh and his friend's consumption of Hekdesh (at his behest) combine to make a Shi'ur for Me'ilah. This law also implies that the prohibition is not one of personal benefit from Hekdesh, but rather one of stealing from Hekdesh.
The proposal that Me'ilah is a form of theft seems to be contradicted by the words of TOSFOS later (21b, DH Perutah). In the Mishnah there, Rebbi Akiva states that when a coin of Hekdesh falls into a wallet containing ordinary coins, the act of taking the first coin from the wallet and using it constitutes Me'ilah. Tosfos asks that the Hekdesh coin should become Batel in the majority of non-Hekdesh coins. (See Insights to Me'ilah 11:1 and 21:3.)
If the Isur of Me'ilah is a monetary law related to theft, then Tosfos' question is not a question. The Gemara in Beitzah (38b) states that when a Kav of one person's wheat became mixed with ten Kavin of his neighbor's wheat, his neighbor certainly is not allowed to eat all eleven Kavin of wheat by claiming that his friend's Kav was Batel. Tosfos there (DH Harei) explains that one cannot compare the laws of a mixture of a prohibited food with the laws of a mixture of two people's property. For prohibited foods, the Torah teaches that we follow the majority. In contrast, when the property of two people becomes mixed, the ownership of the original owner of the minority objects does not become Batel simply because his objects are the minority.
It is evident from there that Bitul b'Rov does not apply to monetary ownership. If the Isur of Me'ilah involves merely a monetary misappropriation, then why does Tosfos (21b) suggest that the coin of Hekdesh should become Batel?
ANSWER: The CHAZON ISH (OC 124, Pesachim 26b, #8) answers that a distinction may be made between removing one coin from the mixture of coins and using all of the coins. When one coin is removed from the wallet, we apply the rule, "Kol d'Parish, me'Ruba Parish," and we assume that the coin that was removed came from the majority of coins which are Chulin. Since most of the coins in the wallet are Chulin, we may assume that no transgression of Me'ilah is committed when one uses the single coin he removes from the wallet. However, if one uses all of the coins in the wallet, he certainly transgresses Me'ilah. We cannot say that the Hekdesh coin was Batel in the Chulin coins, because, as explained above, Me'ilah is an Isur of stealing to which Bitul does not apply. When Tosfos suggests that the Hekdesh coin should be Batel, he refers to when only one coin was removed from the wallet, and not when all of the coins in the wallet were used. (See also the notes of Rav Moshe Feinstein zt'l to Kodshim, printed at the end of IGROS MOSHE OC 1.) (D. BLOOM)

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