This will be the first in a (hopefully long) series of short notes about Choshen Mishpat. Our kehilla started a night program focusing on Choshen Mishpat today. I plan here to make some notes about things that strike me as interesting, confusing, or unclear.

Hopefully, one day, this will develop into a place for chiddushim and birurim. Until then, I plan to use it to store things that I want to make sure I go back to when I have enough information to actually have some answers.

Today’s topic is on קניין כסף. According to the תורה, when a person wants to buy מטלטלין (any moveable object; i.e., not real estate), all he needs to do is pay for it. At the moment he pays, a קניין is effected, and the object (which he didn’t touch, and may be located elsewhere) becomes his.

However, the רבנן saw a possible problem here. The גמרא references a case called “שמא יאמר לו נשרפו חטיך בעלייה”, “Maybe [lest] he [the seller] will say, ‘it was burned in the attic.’” In this case, Reuven bought some wheat from Shimon, and payed him for it. Before Reuven can pick it up, there’s a fire in Shimon’s attic. Shimon has no reason to save the wheat; it’s not his, and he wasn’t a שומר for Reuven. To prevent this from happening, the רבנן said that the קניין doesn’t take place until Reuven does either הגבה (for anything) or משיכה (for things too large to be picked up).

The question is whether this abrogates the original קניין or simply imposes an additional requirement the buyer must fulfill, without which the רבנן decreed that the seller retains responsibility.

For example, let’s suppose Reuven pays Shimon for an item he [Reuven] bought (say, a לולב). We learn above that מדרבנן, the object still belongs to Shimon, and not to Reuven. However, according to the original תורה law, the item is now Reuven’s.

Is Shimon permitted to use the item? For example, in our case above, can Shimon use the לולב on the first day of סכות, when the לולב must be long to the user?