In last week's Parsha (מסעי) we have the dinim of עיר מקלט.
The Gemara in מכות learns out from a Pasuk (in מסעי) that the רוצח בשוגג cannot leave the עיר מקלט even to save the Jewish people. Why not? Some say because he would be putting himself in danger fron the גואל הדם.
Some of the Acharonim (Tiferes Yisroel, Meshech Chochma and others) ask a very simple question on this. Why can't we take away the danger? In other words make sure that the רוצח is not endangered by the גואל הדם. They even offer some concrete suggestions:
1. Make a הוראת שעה that the גואל הדם is not allowed to kill the רוצח and if he (גואל הדם) does he will be killed
2. Lock up the גואל הדם so he can't kill the רוצח
If we do one or both of the above there would then be no danger for the רוצח and he should be able to leave.
The Ohr Sameach (Hilchos רוצח perek 7) deals with suggestion 1 as follows. The Torah specifically allows the גואל הדם to kill the רוצח because כי יחם לבבו. The Torah understands the person and therefore allows him to do this. Therefore we cannot, even as a הוראת שעה, prohibit him from killing the רוצח and/or punish him for doing so as the Torah explicitly permitted it.
The Meshech Chochma (in Masei) has a fascinating solution for the second
suggestion. He suggests that it is not the danger to the רוצח that
we are worried about but rather the danger to the Kohen Gadol. He says
that if we let the רוצח out to save the Jewish people, he may try to
kill the Kohen Gadol in some devious way to free himself from Galus, and
therefore we don't let him leave, because of the danger to the Kohen Gadol.
The Baalei Musar answer the questions as follows. We need to realize that the fate of the Jewish People does not rest on the shoulders of 1 person. As Mordechai said to Esther, רוח והצלה יעמוד ליהודים ממקום אחר, the Jewish People will be saved by someone. Therefore, we don't let the רוצח out of the עיר מקלט to emphasize this point, we should not put our trust in any one person but rather in Hashem.