1. It is called Sharerech (navel) because it sits (in Lishkas ha'Gazis (a chamber in the Mikdash),) in the middle of the world.
2. It is called "Agan" - because it is Magen (protects) the entire world;
3. "Ha'Sahar" - they sit in a (semi-)circle, like the moon;
4. "Al Yechsar ha'Mezeg" - one may leave the Sanhedrin only if at least 23 (the size of a small Sanhedrin) will remain.

1. A Min (heretic): You permit a Nidah to be secluded with her husband. Is it possible that a fire will not singe chips (can he control his desire)?
2. Rav Kahana: The Torah testified about us. "Sugah ba'Shoshanim", we do not breach even a wall of roses.

1. When R. Zeira died, the people realized that until now R. Zeira used to pray for them, but now no one will pray for them! They did a proper repentance.

(a) (Mishnah): To frighten the witnesses in capital cases, we bring them in and say 'perhaps you are speaking through estimation, or what you heard from other witnesses;
(b) Perhaps you don't know that we will check you with Derishos and Chakiros?
(c) You should know that capital cases are not like monetary cases. In monetary cases (if one testified falsely), he could pay and atone for his sin;

1. If one killed through false testimony, he is responsible for the victim's blood, and the blood of all the descendants that would have come from him for all generations.
2. Kayin killed Hevel. It says "Demei (plural) Achicha", showing that he is liable for his blood and that of the descendants destined to come from him.
3. Also, it says Demei because his blood was spilled over wood and stones.

(d) Hash-m originally created only one man, to teach that killing one Yisrael is like destroying an entire world, and saving one Yisrael is like saving an entire world.
(e) Also, this promotes Shalom among people. One cannot say 'my progenitor was created before yours.'
(f) Also, this prevents Minim from saying that there are different powers that created.
(g) Also, this shows the greatness of Hash-m. If a person makes a stamp to mint coins, they all look the same;

1. Hash-m made all people in the mold of Adam ha'Rishon, yet no two people look alike.

(h) Therefore, everyone must say 'the world was created for me.'
(i) Suggestion: Perhaps you (the witnesses) will say 'why should we get involved in this matter (to kill the defendant)'?

(j) Rejection: "V'Hu Ed Oh Ra'ah Oh Yada Im Lo Yagid" - if you saw, you must testify.
(k) Suggestion: Perhaps you will say 'why should we be liable for his blood?'
(l) Rejection: "Va'Avod Resha'im Rinah" - there will not be retribution.'
(m) (Gemara - Beraisa) What is saying by estimation? Perhaps you saw Reuven chasing Shimon to kill him, and you found Reuven holding a sword dripping with blood, and Shimon was murdered and still quivering. If so, you saw nothing (to testify about)!

1. (Beraisa - Shimon ben Shetach): I saw Levi chasing Yehudah into a ruin. I ran after him, and I found Levi holding a sword dripping with blood and Yehudah was murdered and quivering. I said 'Rasha, who killed him, me or you?! However, I cannot do anything - "Al Pi Shenayim Edim Yumas ha'Mes." The One who knows thoughts will punish one who kills another.'
2. Before he moved, a snake bit Levi and killed him.

(n) Question: This was not the proper death penalty for Levi! (A murderer is beheaded with a sword.)

1. (Rav Yosef): After the Mikdash was destroyed, even though the Sanhedrin does not sit (in its place, to judge capital cases), the four death penalties did not cease.
2. Objection: Indeed, they ceased!
3. Correction: Rather, death according to the four death penalties did not cease;

i. One who deserves stoning (Beis Din throws him down from a height; if he survives, they drop a boulder on him, if necessary, everyone throws rocks at him) falls from a roof, or a beast tramples him;
ii. One who deserves burning falls into a fire, or a snake bites him (the venom burns him);
iii. One who deserves the sword, the kingdom kills him (e.g. by a guillotine) or robbers stab him;
iv. One who deserves choking drowns in a river or dies of quinsy (a throat sickness).

(o) Answer: Levi had done another transgression worthy of burning.

1. Someone liable for two different Misos Beis Din receives the more severe one. (All agree that burning is more severe than the sword.)

(p) (Mishnah): (You may not testify) by estimation.
(q) Inference: In capital cases, testimony by estimation is invalid, but it is valid for monetary cases!
(r) Suggestion: Our Mishnah is like R. Acha.

1. (Beraisa - R. Acha): If a dead camel was found next to a mating camel (some say - a camel that bites), we are sure that it killed it.

(s) Objection: We also tell them that Ed mi'Pi Ed (a witness who testifies about what he heard from another witness) is unacceptable. Will you also infer that this is Kosher for monetary cases?!

1. (Mishnah): If he says 'Reuven himself told me', or 'Ploni told me', this is not testimony;
2. He must say 'Reuven admitted to him in front of us that he owes him 200.'

(t) Conclusion: Even though it is also invalid for monetary cases, we tell capital witnesses that it is invalid. The same applies to testimony by estimation.

(a) (Mishnah): You should know (...It says Demei, because his blood was on wood and stones.)
(b) (Rav Yehudah brei d'R. Chiya): This teaches that Kayin wounded Hevel in many places. He did not know where to hit him to kill him, until he struck his neck.
(c) (Rav Yehudah brei d'R. Chiya): From the day that the earth opened its mouth to swallow Hevel's blood, it did not open it again. "Mi'Kenaf ha'Aretz Zemiros Shamanu", we hear from the corner of the earth, but not from the mouth.
(d) Question (Chizkiyah): "Va'Tiftach ha'Aretz Es Piha"!
(e) Answer (Rav Yehudah): It opened its mouth for evil, but not for good.
(f) (Rav Yehudah brei d'R. Chiya): Galus atones halfway. Kayin's judgment was "v'Hayisi Na va'Nod." He only needed to fulfill half, "va'Yeshev b'Eretz Nod."
(g) (Rav Yehudah): Galus atones for three things: "Ba'Cherev uva'Ra'av uva'Dever (one who was liable to die by the sword, hunger or a plague)... v'Nofal Al ha'Kasdim... v'Chayah" (if he will be exiled by the Babylonians, he will live).
(h) (R. Yochanan): Galus atones for everything. "Ha'Ish ha'Zeh Ariri... Lo Yitzlach mi'Zar'o... Al Kisei" (Yechanyah will not have children, and his throne will not pass to his seed). After he was exiled, it says "u'Vnei Yechanyah Asir She'alti'el Beno";

1. His son is called "Asir" because he was conceived in jail;
2. "She'alti'el" - Hash-m was Shosel (planted) him in the womb unnaturally. Normally, a woman does not get pregnant through Bi'ah while standing (the semen falls out), but his mother did. (There was no room in the jail cell for them to lie down.)
3. Also, he is called She'alti'el because Hash-m was Sho'el on (permitted) His vow that Yechanyah would not have children.
4. His son is called Zerubavel because he was Nizra (conceived) in Bavel;
5. His son's true name was Nechemyah ben Chachalyah. (The Ramah asks that he was the son of Yechanyah. Also, verses list Zerubavel separately from Nechemyah! Margoliyas ha'Yam answers that 'ben Chachalyah' means 'the son of one who was Chayav Kelayah (worthy to be destroyed)', and a different Nechemyah was listed with Zerubavel.)