One of the topics addressed in Parashat Mishpatim is nizkei mamon – liability for damages caused by one’s property, such as by his animal. The famous opening Mishna of Masekhet Bava Kama lists the various categories of damage liability, and concludes by noting that the common denominator between them is “shemiratan alekha” – one bears the obligation to guard them. Underlying the entire concept of liability for nizkei mamon is a person’s responsibility to control his possessions so they do not cause damage to other people’s bodies or property. (See also the Mishna later, 9b – “Kol she-chavti bi-shmiratan hikhsahrti et nizko.”) Indeed, if one took the proper measures to protect against damage caused by his property – such as by properly restraining his animals – but his property nevertheless caused damage through circumstances beyond the owner’s control, he is absolved of liability. Since he fulfilled his responsibilities, and the damage occurred due to circumstances which he could not have foreseen or prevented, he is exempt.
A number of Acharonim addressed the question as to the precise Biblical source of this obligation. Where does the Torah introduce a requirement to take reasonable measures to prevent one’s possessions from causing damage? While we intuitively understand the importance of this requirement, where it is mentioned in the Torah?
The Chatam Sofer (Y.D. 241) suggested that this obligation falls under the command of “lo ta’amod al dam rei’ekha” (Vayikra 19:16), which requires assisting somebody who faces danger. The classic case discussed by Chazal (Sanhedrin 74a) is when one’s fellow is drowning, and the person is in a position to rescue him. The command of “lo ta’amod al dam rei’ekha” forbids remaining idle in such a case, and requires one to do what he can to rescue his fellow from danger. This obligation, the Chatam Sofer contends, also includes taking proactive measures to ensure not to endanger other people through unsafe conduct or by allowing one’s possessions to cause harm.
The Chatam Sofer seems to have understood that if the Torah requires us to rescue somebody who faces danger even though we are not at all at fault for his dire situation, then certainly we must not place him in a situation of danger – either physical or financial. To that end, we are required to handle our possessions in such a way that they do not cause harm to other people or their possessions.
However, Rav Asher Weiss questions this approach, noting that it fails to explain the specific obligation one bears with respect to his own property. If the requirement of shemirat mamono – protecting against harm caused by one’s possessions – stems from the general obligation to save others from harm, then why is it limited to one’s own possessions? Even if we assume that “lo ta’amod al dam rei’akha” includes actively working to ensure public safety, then why do people bear a specific requirement with respect to their own possessions? Seemingly, we should be required to protect people from all harm, even from the harm posed by other people’s possessions.
The answer, perhaps, is that while this fundamentally is correct, and in principle we are to prevent all hazards of any kind, even those posed by others, in practice, the requirement of shemirat mamono has to be restricted to one’s own possessions. It is clearly impractical to expect all people to prevent all hazards. The most feasible way for the Torah to practically apply the obligation to maintain safety is to demand that every person act safely and prevent his possessions from causing harm. Of course, if we see somebody else’s animal threatening another person, and we are in a position to help, the command of “lo ta’amod al dam rei’ekha” requires us to intervene. But when it comes to restraining animals to prevent them from causing harm, this prohibition requires each person to control his own possessions.