It is often hard for us to realize that concepts we take for granted are foreign to others. That helps explain why so many in the Western world are often shocked by events on the other side of the world. Concepts that for us are second nature were (and for some, still are) revolutionary in their time. We often fail to appreciate just how revolutionary the Torah was--in its treatment of the foreigner, in its demand for a day of rest for slaves, in requiring equal justice for all and the giving of tzedakah, to name just a few.
As little kids, we were taught, "finders keepers, losers weepers". This was the norm in the ancient world--until the Torah came along and created a new paradigm. "You shall not see the ox of your brother or his sheep wandering and ignore them; you must return it to him" (22:1). The Torah goes even further, demanding that we bring the lost object (or animal) into our home for safekeeping until we can connect owner and object.
One of the great side effects of the mitzvah of aliyah leregel, the requirement to visit the Temple three times a year, was the opportunity to fulfill this mitzvah. The Temple served as a huge lost-and-found. The point at which a finder of an object could keep it was connected to the amount of time it took for a pilgrim to travel to the Temple and see if anything was missing.
For a Jew, returning a lost object is to be second nature. Traditionally, Jews begin Talmud study with "Eilu Metziot", the second chapter of Bava Metzia. "These are the objects which one can keep, and these are the objects which one must declare". This chapter not only introduces a student into the intricacies of Talmudic debate and logic; more importantly, it served to reinforce, even if only subconsciously, the importance of returning a lost object.
One of my favorite Talmudic stories--and one I taught my children at a very young age--is that of Shimon ben Shetach, one of the earliest known rabbinic figures. The Midrash relates how he purchased a donkey (he was quite poor, and needed the donkey to help in his menial labour) from a heathen. His students, in surveying the animal, excitedly told Shimon ben Shetach that he was now a rich man, as the donkey contained a jewel. Shimon ben Shetach immediately responded, "Do you think I am a barbarian? I bought a donkey, not a jewel; go and return it to the Ishmaelite". Upon his doing so, the Ishmaelite exclaimed, "Blessed is the G-d of the Jewish people!" (The sanctification of G-d's name is always accomplished by ethical greatness, not by increased ritual piety.)
Rabbinic exegesis expanded the parameters of returning a lost object. The requirement to return a lost object was interpreted as a mandate to a physician to return a person to good health. The Rabbis understood that monetary concerns can and do have an impact on one's health. This is especially true when it comes to lost items, as research has demonstrated that people feel about twice as much pain when they lose something as joy when they gain something.
The Torah concludes the mitzvah of hashavat aveidahwith the admonition, "you are not allowed to ignore". Returning a lost object can be a pain (and Jewish law does not require one to actively lose money to perform this mitzvah), and it can be so much easier to look the other way and pretend not to see the object.
Here, too, it is most appropriate to expand the meaning of the verse. We often can't be bothered to greet people, to call and see how they are doing, or to lend a helping hand. We can pretend we do not see, and ensure we do not hear. The same applies to communal challenges. That is not the way one may act. There is so much that must be done to make this world a better place, to return it to its pristine state. You may not ignore.