QUESTION: The Gemara (end of 58b) cites the Beraisa that teaches that Terumah can be separated "b'Machshavah," with mental intention alone and without a verbal declaration. This is derived from the verse, "v'Nechshav Lachem Terumaschem" (Bamidbar 18:27).

REBBI AKIVA EIGER (Teshuvos, #29) asks that if Terumah can be separated through Machshavah, then why does one recite a blessing when he separates Terumah? The BEIS YOSEF (OC 43:2) writes that the Rabanan did not institute a blessing for any Mitzvah that can be fulfilled with Machshavah, with thought. Why, then, does one recite a blessing when he separates Terumah, when Terumah can be separated through Machshavah?

ANSWER: The MAHARIT (#127) discusses another difference between speech and thought. He writes that one cannot appoint a Shali'ach to sanctify an animal (as a Korban) on one's behalf, because the sanctification of an animal is performed through speech, and a Shali'ach cannot be appointed to carry out a mission that involves speech -- "Mili Lo Mimseran l'Shali'ach" (Gitin 66b). The Maharit questions his own assertion from the laws of Terumah. Terumah may be separated through thought, which is not more powerful than words, and yet a Shali'ach may be appointed to separate Terumah on one's behalf!

The Maharit cites TOSFOS in Kidushin (59b, DH Miyad) who says that the verse "v'Nechshav Lachem Terumaschem" teaches that separating Terumah through Machshavah is akin to separating Terumah with an action, with one's hands. Accordingly, it is not considered a matter of "Mili," and a Shali'ach may be appointed to separate one's Terumah.

Similarly, even though the Rabanan did not institute a blessing for a Mitzvah that can be fulfilled through Machshavah, one recites a blessing for separating Terumah, because the Machshavah of Terumah is equivalent to separating Terumah with one's hands. (See Insights to Menachos 2:2.)

QUESTION: The Gemara (end of 58b) cites the Beraisa that teaches that Terumah can be separated "b'Machshavah," with mental intention alone and without a verbal declaration. This is derived from the verse, "v'Nechshav Lachem Terumaschem" (Bamidbar 18:27).

RASHI (DH b'Machshavah, in his second explanation) explains that separating Terumah through Machshavah means that the person looks at one side of the produce and decides that the fruit there will be Terumah. He then may eat the fruit from the other side even before he physically separates the Terumah produce.

TOSFOS (DH b'Machshavah) adduces proof that one may separate Terumah without any verbal declaration from the Mishnah in Terumos (1:6). The Mishnah there says that a person who is mute should not separate Terumah l'Chatchilah, but if he did separate Terumah, the Terumah is valid. The Yerushalmi explains that the reason why he should not separate Terumah l'Chatchilah is that he cannot recite the blessing (since he is mute). His Terumah is effective b'Di'eved because, as the Gemara here teaches, Terumah may be separated through Machshavah and speech is not essential in order to separate Terumah.

If it is possible to separate Terumah merely by looking at one side of the fruit and eating from the other side, then why is it prohibited to separate Terumah on Shabbos and Yom Tov? The Mishnah in Shabbos (141b) cites Rebbi Yehudah who says that when one Se'ah of Terumah fell into one hundred Se'ah of Chulin (such a mixture is called "Meduma"), one is permitted to remove one Se'ah from the mixture in order to permit the rest. The Gemara there (142a) asks why this is not considered "Tikun" on Shabbos; since one is making the fruit usable on Shabbos, it should be prohibited by the Gezeirah that prohibits performing any act of Tikun of food (due to the concern that one might also be Metaken a utensil and transgress a Melachah d'Oraisa). The Gemara answers that Rebbi Yehudah follows the view of Rebbi Shimon ben Elazar who says that in the case of Terumah that fell into Chulin, one may look at one side of the produce and eat from the other side. Since one may eat the produce by separating the Se'ah merely through thought, it is not considered to be an act of Tikun on Shabbos.

Why, then, is it prohibited to separate Terumos and Ma'aseros on Shabbos? Since Terumah may be separated through thought, without any action, it should be permitted on Shabbos, as is evident from the Gemara in Shabbos!

(a) TOSFOS (DH b'Machshavah) answers that separating Terumah through Machshavah is permitted only in a case of "Meduma," a mixture of Terumah and Chulin. Since the actual fruit of Terumah was separated before Shabbos, the prohibition of "Tikun" of food on Shabbos does not apply, and one is permitted even to remove the fruit manually. In contrast, one may not be Metaken actual Tevel from which Terumah was never separated, because this is an actual Tikun of the food and is prohibited.

Tosfos proves from the Mishnah in Shabbos (34a) that separating Terumah from Tevel is a greater form of Tikun than separating fruit from a mixture of Terumah and Chulin. The Mishnah says that one is permitted to separate Ma'aser from Demai (produce of an Am ha'Aretz from which one is obligated to separate Ma'aser mid'Rabanan, due to a doubt about whether Ma'aser was separated already) only during Bein ha'Shemashos, when there is a doubt about whether it is day or night, but not when it is definitely Shabbos. On Shabbos itself, one may not separate Ma'aser from Demai, even though one can separate Ma'aser by looking at one side of it and having in mind that the fruit on that side is Ma'aser (and then one may eat from the other side), as the Gemara teaches in Chulin (6b).

(b) REBBI AKIVA EIGER answers that according to the conclusion of the Gemara in Shabbos (142b), the opinions of Rebbi Yehudah and Rebbi Shimon ben Elazar are not exactly the same. Rebbi Yehudah maintains that since it is possible to be Metaken the Meduma by looking at one side and eating from the other side, the Halachah does not require him to actually do this, but one may even remove the Terumah manually on Shabbos from the mixture. In contrast, Rebbi Shimon ben Elazar allows this Tikun only by thought, but not by actually removing the Terumah. Accordingly, the Mishnah in Shabbos (34a) that says that on Shabbos it is prohibited to be Metaken even Demai manually is following the opinion of Rebbi Shimon ben Elazar, because Rebbi Yehudah maintains that it is permitted to separate Ma'aser from Demai on Shabbos. However, the Halachah follows the view of Rebbi Shimon ben Elazar and the Mishnah in Shabbos (34a) that one may not separate Ma'aser from Demai on Shabbos. (D. BLOOM)