Q: On Purim I was fundraising door-to-door with a group of friends. We approached Reuven and asked him if he could donate generously to this cause. He replied that if we went to Shimon’s house and convinced him to donate $100, he (Reuven) would match that donation. We knocked on Shimon’s door, told him about Reuven’s offer, and asked him to donate $100. We explained that he would earn a double zechus, because his contribution would bring in a matching donation. He agreed in theory, but he said that we first had to check whether Reuven would truly be obligated to fulfill his verbal pledge.
Is Reuven obligated to keep his commitment?
A: We must first determine whether Reuven made his offer because he was certain that Shimon wouldn’t donate $100. If that was his thinking, then he is not required to fulfill his pledge, because it is in the category of nidrei shegagos (vows made in error). A passuk in the Torah (Vayikra 5:4) implies that a person is obligated to fulfill a vow only if it was made with full intent, not if it was based on erroneous assumptions (Shulchan Aruch, Yoreh De’ah 232:6).
If Reuven did consider it at least a possibility that Shimon might grant your request, the next question to address is whether a verbal commitment is enough to obligate a person to fulfill a pledge if he did not make a kinyan to formalize it.
In this regard, a verbal commitment alone is binding without a kinyan, because a pledge made to tzedakah is considered a neder (vow) (ibid. 258:12 and C.M. 243:2). But we must still consider the possibility that Reuven would not be obligated to fulfill his pledge because of the halachah of asmachta lo kanya.
An asmachta is an agreement a person makes under the assumption that he won’t actually have to fulfill it. (For instance, wagers are asmachtas, because every person who places a bet thinks he will win.) In this case, if Reuven agreed to match Shimon’s donation only because he assumed that Shimon might not be willing to give, presumably his pledge is not binding (ibid. C.M. 207:13).
We see from two vows in the Torah, however, that this assumption might not be correct.
After waking from his dream with the ladder, Yaakov Avinu vowed: If Hashem will be with me... everything You give me, I will repeatedly tithe to You (Bereishis 28:20-22). And when Amalek attacked and took a hostage, Bnei Yisrael vowed that if they defeated their enemy, they would consecrate all the spoils of war to Hashem (Bamidbar 21:2).
Both of these vows could be categorized as asmachtas, because in both the vow was contingent upon a specific outcome — yet they were seemingly considered binding.
Some Rishonim infer from this that whenever a person makes a vow or takes an oath, it is never considered an asmachta (Maharam MiRottenberg, Prague Edition 494). This approach is codified in Halachah (C.M. 207:19; and Yoreh De’ah 258:10 with Nekudos Hakesef).
Other Rishonim argue that the aforementioned episodes in the Torah are inherently different. Those vows were likely to have been made with full intent because they were made in order to merit salvation or Divine assistance. Therefore, when the salvation or assistance was received, the person who made the vow affirms it in his mind. Consequently, if a person asks Hashem to help him through a situation, and he promises to fast or give tzedakah when he receives that assistance, those pledges are not considered asmachtas (Orach Chaim 562:13, with Magen Avraham 17).
If, however, a person vows to give tzedakah or fast if he does a certain dvar hareshus (an action that is not a mitzvah), and he is not sure that he will do that action, it is an asmachta.
But if a person is trying to bolster his commitment to do a mitzvah, and he pledges to fast or give tzedakah if he fails to do that mitzvah, it is not an asmachta (Rabbeinu Yerucham, Toldos Adam v’Chavah, Nesiv 19, cited in Orach Chaim, loc. cit).
According to this opinion, in your case, where Reuven’s intention was not meant to commit himself to do another mitzvah, it would be considered asmachta and he would not have to match Shimon’s donation.
In practice, since the poskim (Magen Avraham 562:16 and Mishnah Berurah 54) rule according to the first approach, if Shimon donates the $100, Reuven must match it even though his pledge was an asmachta (see however BHI #637).
