1) A key to understanding the limits to which we are expected to go in order to fulfill the Mitzvah of Hashavas Aveidah may be found in the Mishnah in Bava Metzia 33a, where we learn that if one's own property is in danger and the property of someone else (even his own father) is in danger, and he can save only one person's property, his own property takes priority.

Rav Yehudah, in the Gemara, teaches that this is derived from Devarim 15:4, "There shall be no poor among you (Becha)." Rashi (DH Lo) explains that the Torah here commands us to be careful not to become poor.

The word "Becha" -- "in you" -- tells us that first one must ensure that "you" do not become poor. Afterwards, one has a Mitzvah to care for the property of others.

Therefore, the Halachah is that "your property takes precedence over the property of any other person."

2) A similar idea is found in the Mishnah above, 30b, which discusses someone who is in the middle of earning money when the Mitzvah of Hashavas Aveidah comes his way. The time that he will lose from his work in order to return the lost item will cause him to forfeit earning a "Sela" coin. If there are three people available, in front of whom he can declare that he is prepared to return the lost item only if he will be reimbursed with a Sela, he may make this agreement. If there are not three people available, his own livelihood comes first and he is exempt from the Mitzvah of Hashavas Avedah.

3) On the basis of the above we can say that one is not obligated to incur damages in order to be a good neighbor. However, if one can come to an agreement with the neighbors whereby one could save their property, and also be repaid for any losses suffered such that a greater total loss would be avoided, such an arrangement would certainly be recommended.

4) However, there is a very important addition to the Gemara on 33a that I cited (above in 1). Immediately after Rav Yehudah said that "your property takes precedence," he qualified this by stating: "Anyone who behaves this way will eventually need the help of others."

Rashi explains that the Torah does not obligate us to do Hashavas Aveidah if it costs us money. On the other hand, a person should act within the letter of the law and should not be so pedantic about a small loss that he might incur because of the Mitzvah. It is only when there is a clear financial loss that he should say "I come first." Rashi writes that if someone is never prepared to suffer a small loss, this means that he has relinquished the Mitzvah of helping others and in the end he himself will have resort to receiving charity from others.

5) I suspect that the above idea may shed light on the scenario where the neighbor refused to build a wall to prevent his friend's field from being flooded, because he argued that this may prevent him from having water for the next season. Every case would have to be judged on its merits, but this may well be an example of a person suffering a small loss in order to prevent a major loss on the side of his friend. The Beis Din could not force him to suffer such a loss, but the Gemara says that one should say "I come first" only in cases of significant losses.

Kol Tuv,

Dovid Bloom

Now to the question of whether one is required by the Torah to get hurt in order to perform the Mitzvah of returning lost property.

1) First, we should consider the question of whether one is required to become sick (even if no danger to life at all is involved) in order to perform any Mitzvah of the Torah. See Igros Moshe, Orach Chaim 1:172, who writes that in a scenario in which one could perform the Mitzvah of hearing the Shofar on Rosh Hashanah only by becoming ill as a result, he is not required to do the Mitzvah. The proof for this is that one is required to spend only up to one fifth of one's money in order to perform a positive Mitzvah. Since a person would spend a fifth of his money to recover from illness, it follows that prevention of illness is more important to people than money. Since one is not required to spend more than a fifth of one's money in order to perform a positive Mitzvah, it follows that one is not obligated to "spend his health" and become ill in order to perfom a Mitzvah.

2) We learn from the above that one does not have to become ill in order to do the Mitzvah of returning lost property, according to Rav Moshe Feinstein zt'l, but the question does still remain whether one is required to suffer pain, when one does not actually become ill from this. I am not going to answer this question exactly at the moment, but will discuss a different, related question: Is one required to make a considerable effort to perform the Mitzvah?

We can start this discussion by looking at the Gemara in Nedarim 37a which tells us that one is not allowed to receive payment for learning Torah. This raises a problem, because the Mishnah in Nedarim 33a tells us that there are some places where they receive pay for returning lost items. The Tosfos Yom Tov there asks how can this be? Since returning a lost object is a Mitzvah it should follow that just as one may not receive pay for teaching Torah, one also may not receive pay for doing any Mitzvah!

To answer this question I would like to make a Diyuk in Rashi to Kesuvos 108a, DH b'Makom. Rashi explains the Mishnah in Nedarim, that in some places they receive pay for Hashavas Avedah, to mean that in fact they get paid for the "Tircha," the effort of returning the lost item. We see from Rashi that while one is not allowed to be paid for a Mitzvah, this means a Mitzvah which does not involve significant effort. If it involves a lot of work, the Torah does not obligate one to do it for free.

I should really write more at length on this subject, but I do not want to make things too complicated. I will just refer to the Even ha'Ezel, Hilchos Gezeilah 12:3, where Rav Isser Zalman Meltzer zt'l writes at length about what level of effort one is obligated to go to in order to do the Mitzvah of Hashavas Avedah.

Kol Tuv,

Dovid Bloom