The Beraisa requires three judges for Dinei Mamonos. A single judge is permitted however - provided he is an expert.

The Tana ignores the triple "Elohim" written in the Parshah - because he does not hold of 'Eiruv Parshiyos' (like Rava in the Sugya above [see also Tosfos DH ve'Im').

Rav Nachman and Rebbi Chiya both declared that - they were good examples of experts who had the authority to issue rulings on their own.

We think that, besides expertise, Rav Nachman and Rebbi Chiya might also have perhaps required - permission from the Resh Galusa (the exilarch) or from the Nasi (Semichah) to act as individual judges.

If they did not receive permission to rule (assuming that the litigants did not accept them), they would then be obligated to pay if they erred.

We resolve the She'eilah from Mar Zutra b'rei de'Rav Nachman - whom Rav Yosef instructed to pay, when he erred in one of his rulings (assuming that the litigants did not accept him), a proof that his ruling was at least, valid (so we see that an expert's rulings are valid, even without express permission from the ruling power (otherwise, Rav Yosef would have instructed him to simply negate his initial ruling, rather than pay from his own pocket).

Both Rav and Shmuel advise someone who wants issue rulings and be Patur from paying in the event that he errs in one of his rulings - to obtain permission from the Resh Galusa.

Regarding the Pasuk in Vay'chi "Lo Yasur Sheivet mi'Yehudah ... ", the Beraisa explains - that "Sheivet" refers to the Resh Galusa (in Bavel who ruled the people with a staff); and "Mechokek", to the Nasi in Eretz Yisrael.

Fhe Tana describes ...

... the Resh Galusos in Bavel as - leaders who ruled the people with a rod.

... the Nesi'im in Eretz Yisrael as - the descendents of Hillel who taught Torah in public.

The Resh Galusa in Bavel had more authority than the Nasi in Eretz Yisrael - because he had the backing of the King of Persia.

The ramifications of this distinction are that - whereas permission helps from Bavel to Eretz Yisrael, it does not help the other way round.

We learn the seniority of the Resh Galusa over the Nasi in Eretz Yisrael from an episode with Rabah bar Chanah, to whom Rebbi Chiya once told, when he erred in a case concerning money-matters - that, unless the litigants initially accepted him, he would have to pay (because he did not receive permission from the Resh Galusa).

Rabah bar Rav Huna claimed that he received permission from his father ... who received permission from Rebbi - when he was once arguing with the Resh Galusa.

The names of the two men missing from the list (between Rav Huna and Rebbi) are - Rav and Rebbi Chiya.

There is no proof from Rabah bar Rav Huna's statement that it does help to receive permission from Eretz Yisrael to rule in Bavel - because Rabah bar Rav Huna's statement was meant to show how great his Rebbes were, even though it had no legal ramifications.

Despite the fact that permission does not help from Eretz Yisrael to Bavel, they gave Rabah bar Chana Semichah when he left Eretz Yisrael to go to Bavel - to issue rulings in the areas surrounding Bavel that belonged to Eretz Yisrael.

When Rebbi Chiya informed Rebbi that his brother's son was going to Bavel, he (Rebbi Chiya) asked him three questions ...

... 'Yoreh?' ('May he issue rulings in Isur ve'Heter?')

... 'Yadin?' ('May he issue rulings in money matters and be exempt from paying should he err)?

The significance of 'Yatir Bechoros' is - to permit a B'chor to be Shechted by the Kohen without having to bring it as a Korban, due to a permanent blemish that the Kohen had not performed deliberately.

Rebbi replied - 'Yoreh', 'Yadin', 'Yatir Bechoros'.

When Rebbi Chiya asked Rebbi the same questions regarding his sister's son, the latter replied - 'Yoreh', 'Yadin' but 'Al Yatir'.

Rebbi Chiya's ...

... brother's son was - Rabah bar Chanah.

... sister's son was - Rav.

Ayvu, Chanah, Shiylo, Marsa and Rebbi Chiya - were all brothers.

Rav's father was - Ayvu.

Aba bar Acha Kars'la from Kafri - was the father of the five brothers.

Rebbi Chiya referred to Rabah as his brother's son, and Rav as the son of his sister - because Rav's father happened to have married the half-sister of his half-brother (Rebbi Chiya), in which case Rav was the son of both Rebbi Chiya's half-brother and his half-sister.

Another reason for referring to Rav as his sister's son is based on the Pasuk in Mishlei - "Emor la'Chochmah Achosi At" ([see Agados Maharsha] with reference to Rav's vast knowledge).

The reason that Rebbi did not agree to grant him permission to rule in matters to do with B'chor could not have been because he was ...

... not very smart - because he was exceedingly smart, as we just explained.

... not conversant with the Halachos of a B'chor - because, after Rav had spent one and a half years studying the laws of B'chor, Rebbi could hardly have meant that.

The reason that we initially give for Rebbi's refusal to grant Rav 'Yatir Bechoros' is - in deference to his half brother Rabah bar Chanah, who was perhaps not as brilliant as him, but deserving of the limelight nonetheless.

It may well be that Rebbi did not agree to give Rav Semichah to permit Bechoros, precisely because of his phenomenal expertise - out of concern that he would permit Bechoros on the basis of blemishes that were unknown to the people, and they, in their ignorance, would extend his rulings to permit animals with temporary blemishes.

We query the concept of receiving permission to issue rulings - on the grounds that if the applicant is an expert, why should he require permission?

We attribute it to a decree of Rebbi, who once discovered the people in a certain town preparing their dough be'Tum'ah.

The people of the town explained to him that a certain Talmid-Chacham had taught them that 'Mei Betza'im' - water from marshland, is not Machshir Lekabeil Tum'ah'.

What the Talmid-Chacham had really said was that - 'Mei Beitzim', the white of eggs, that is used to knead eggs, is not Machshir.

This caused Rebbi to react the way he did - to encourage the Rabbanan to be more careful when teaching Halachos.

They also erred with regard to a Mishnah in Parah, where the Tana says - that the water of the Rivers Karmiyon and Pigah are Pasul (for the use with ashes of the Parah Adumah).

The basis of their mistake was - that the reason of the Tana there is because the water of those two rivers is not considered Mayim Chayim (spring water), which does not mean that it is not water as far as Machshir le'Kabeil Tum'ah is concerned.

'Lesisah' is - soaking wheat for a short while in water, before grinding it. It is permitted on Pesach, since one grinds it immediately, and it doesn't have a chance to rise.

Rebbi Tanchum b'rei de'Rebbi Ami should not have Darshened this Heter in Chatar - since his Rebbe, Rebbi Mani from Tzur lived there, and a Talmid is not permitted to issue rulings within three Parsah (twelve Mil) of his Rebbe.

When the people queried him about this, his response was - that he had not realized that Rebbi Mani lived there.

When Rebbi asked the son of a Kohen what he was doing in a Beis-Hakevaros, he replied - that his father had brazenly taken a fancy to a divorcee, whom he had subsequently married, and that he was the product of that marriage, and was therefore a Challal, who is allowed to become Tamei Meis.

This story is cited here - because Rebbi Chiya had rebuked the man in the vicinity of Rebbi, and it comes to teach us, that when it comes to preventing someone from sinning, the previous Halachah of not ruling in the vicinity of one's Rebbe, falls away (because Kavod Shamayim takes priority over Kavod ha'Rav).

We could also explain the connection between this story and that of Rebbi regarding the people who kneaded their dough be'Tum'ah, according to the Yerushalmi, which reads - a. Rebbi instead of Rebbi Chiya, and b. that Rebbi discovered the Kohen in Acco (part of which is considered Chutz la'Aretz, and therefore has a Din of Tum'as Meis).

That explains why the story is brought here - because both episodes occurred when Rebbi went to Acco - the first one in the part of Acco that was Eretz Ysrael, the second one, in the part that was Chutz la'Aretz, respectively (and he queried the Kohen based on the fact that the Chachamim decreed Tum'ah on Chutz la'Aretz).

We already learned that it is possible to give partial Semichah, as we saw with Rav. When Rebbi Yochanan told Rav Sh'man that he was 'in his (Rebbi Yochanan's) R'shus until his return', he meant that - he granted him permission to issue rulings until he returned to Yerushalayim.

We earn from there - that a Semichah on condition too, is valid until the condition is fulfilled.

Earlier, we cited the opinion of Shmuel, who learned earlier that if two judges adjucated, even though they have earned the title 'Beis-Din Chatzuf, their rulings are nevertheless valid. Rava asked Rav Nachman on Shmuel from a Mishnah in 'Zeh Borer'. The Tana there says in a case where two judges rule Patur or Chayav, but the third one does not know - that they are required to add judges.

This poses a Kashya on Shmuel - according to whom the initial two judges should be able to conclude the case on their own.

Rav Nachman replied that this case is different than Shmuel's - since they began with three judges, they must conclude with at least three, unlike Shmuel's case, where two judges opened the proceedings.

The Halachic distinction that Rabban Shimon ben Gamliel makes between Din and P'sharah is that - whereas the former requires three judges, the latter requires only two.

And he then presents the stringency that P'sharah has over Din that - whereas the litigants are permitted to retract from a Din that is issued by two judges, they cannot retract from a P'sharah that is issued by them.

We try to refute the suggestion that the Rabbanan dispute Raban Shimon ben Gamliel's ruling with a statement by Rebbi Avahu who says that - if two judges issue a ruling, everyone agrees that their ruling is void.

We counter that argument however - based on the principle 'Gavra a'Gavra ka'Ramis?' How can you ask from Rebbi Avahu on to Shmuel? The former holds that there is no Machlokes Tana'im, whereas the latter holds there is (and he holds like the Chachamim).