(Mishnah): A Ben Sorer u'Moreh is not killed for his sin, rather, due to his future. It is better for him to die before he sins even more.

Death of Resha'im is good for them (for this reason), and this is good for the world. It is bad for Tzadikim (they cannot do more Mitzvos), and bad for the world.

Wine and sleep are good for Resha'im, and this is good for the world. These are bad for Tzadikim, and this is bad for the world.

Scattering of Resha'im is good for them, and this is good for the world (they cannot conspire together). It is bad for Tzadikim, and bad for the world.

Serenity of Resha'im is bad for them, and this is bad for the world. It is good for Tzadikim, and good for the world.

(Gemara): Hash-m saw that this [Ben Sorer u'Moreh] will later exhaust the property of his father and mother, and he will sit at the crossroads and rob people and kill people, and in the end he will forget his learning. The Torah said that it is better that he die Zakai, and not die Chayav. Death of Resha'im is good for them, and good for the world. It is bad for Tzadikim, and bad for the world.

Wine and sleep are good for Resha'im, and this is good for the world. They are bad for Tzadikim, and this is bad for the world.

(R. Avahu): Only wine and much sleep [are bad for Tzadikim];

(R. Yonason): [Tzadikim] sleep a little, so their mind will be settled. (This help for learning Torah.)

(Mishnah): A Ba b'Machteres (a thief tunneling into a house) is judged (i.e. one may kill him) due to what he plans to do at the end (this will be explained).

If a Ba b'Machteres broke a barrel - if he has blood (he may not be killed), he is liable. If he has no blood (he may be killed), he is exempt.

(Gemara - Beraisa - R. Yishmael): This is one of three verses in the Torah that were said as parables. "Im Yakum v'His'halech ba'Chutz Al Mish'anto" (it does not depend on walking with a stick. Rather, if he recovered, even if he died later, the one who struck him is exempt);

"Im b'Machteres Yimatzei ha'Ganav Im Zarchah ha'Shemesh Alav Damim Lo" - does the sun shine only on him? It shines on the entire world!

Rather, just like shining of the sun is Shalom for all inhabitants of the world, as long as you know that you are at peace with him (he does not intend to kill you), whether during the day or at night, one who kills him is killed (he has blood).

If it is a Safek if he comes [only] to steal, and a Safek if he comes [even] to kill - if Vadai he comes to steal, and one killed him, the one who killed him is killed. If it is a Safek that he comes to kill, he is killed.

From here you learn to Piku'ach Nefesh to say that just like murder is special, that it is Metamei the land and desecrates Hash-m's name and maks the Shechinah depart, and a Safek overrides it (we kill a thief when there is a Safek about his intent), all the more so Piku'ach Nefesh, a Safek overrides (Shabbos or other Isurim). (HAGAHOS R. DINAR)

(R. Chiyah): "Im b'Machteres Yimatzei ha'Ganav v'Hukah u'Mes Ein Lo Damim" - in the tunnel he has no blood, but outside the tunnel he has blood.

(R. Shimon ben Yochai): Even outside the tunnel he has no blood, for a person's money is dear to him like his soul. When [the thief] sees that [the owner] wants to take back his property, he will stand against him and kill him.

(Rav Huna): If [the thief] took the wallet and turned to face to leave, and [the owner] stood against him and killed him, the murderer is not killed.

1. What is Rav Huna's reason? It says "Ki Yicham Levavo." (The owner is enraged that his property was taken, and if he wants to take it back, the thief will kill him. Therefore, he may kill him first.)

Rav: Anyone who comes against me [in a tunnel], I would kill him, except for Chananyah ben Shila, for I know that [he loves me greatly and would never kill me;] he comes only to take my food and my property.

R. Yitzchak: Since his heart is brazen to do this [tunnel in], he is not [acting like] Chananyah ben Shila! (He is suspected to kill.)