Laws of War Excerpted and adapted from a shiur by Dayan Yitzhak Grossman November 30,…
Excerpted and adapted from a shiur by Dayan Yehoshua Grunwald
September 17, 2021
On the first two days of Sukkos, one must own the arba’ah minim in order to fulfill the mitzvah of taking them. Those who do not own their own arba’ah minim generally use someone else’s set via matanah al menas lehachzir (giving a gift on the condition that it is returned afterward). But it is not clear whether tenai kaful (a double condition, i.e., where both the “if” and “if not” possibilities are expressed), which is necessary for conditions in other areas of halacha, is required here.
According to the Smag, one must make a tenai kaful when giving a matanah al menas lehachzir for arba’ah minim. The Mordechai disagrees and notes that Rishonim debate whether a tenai kaful is necessary for conditions outside of gittin and kidushin (such as for mamonos). The Mordechai states that the halacha follows the Rashbam that it is unnecessary for mamonos. The Bais Yosef (O.C. 658) cites this machlokes and rules that we follow the Mordechai with regard to arba’ah minim.
Although the Bais Yosef elsewhere (E.H. 38) cites both opinions and does not rule definitively like the Rashbam, the case of esrog may be more lenient for a number of reasons. These include the fact that perhaps there is a clear umdena that one wants the tenai to be valid even without the tenai kaful (Tosafos Kidushin 6b); tenai kaful may be unnecessary for metaltelin (Nesivos Hamishpat C.M. 207); and that even if the tenai kaful is needed but not performed, the recipient will still own the arba’ah minim (just that the condition of al menas lehachzir is invalid and it will not revert back to the owner) (Remach).
Some Acharonim are machmir that a tenai kaful should be added when borrowing arba’ah minim (Bikurei Yaakov; the Brisker Rav, cited in Mo’adim Uzmanim). However, the Kaf Hachaim rules that it is not needed, and it would seem that due to the considerations above, this is the basic halacha.