This mitzvah is one of a group which require a person to be considerate of others' rights and possessions.Examples include returning a lost object to its rightful owner, helping load and unload a beast of burden, lending money to the needy, etc. According to the Talmud, the above verse means that we should not stand idly by while someone else's possessions are being destroyed, if we can do something to save them. The uniqueness of this verse lies in the graphic image used: standing idly by while another's blood is being shed.
I often receive calls such as this: "A friend of mine is drinking far too much, and I see that he is in the process of ruining himself. What can be done for him?" When I explain to the caller that as a true friend, he should try to approach his friend and, in as gentle and non-judgmental terms as possible, inform him of his concern, the answer is usually, "I don't want to get involved. Isn't there something that you can do?"
Alcohol is not necessarily the only problem that may ruin us. We may observe a person entering into a business venture with someone known to be unscrupulous and opportunistic, or into a relationship which we believe is a serious mistake. It may not be pleasant to try to deter a person from whatever path he or she is taking, and we may indeed be told to mind our own business. Nevertheless, we should not shirk from making the effort. Even advice that is initially ignored may make an impression and lead to reconsideration.
If the Torah had used less forceful words, we might indeed take refuge and mind our own business. The metaphor of considering it equivalent to standing idly by and watching someone's blood being shed emphasizes the gravity of the responsibility to prevent others from harming themselves.