Rabah explains that he only means that the Nazir is allowed to touch another
Mes while he is still in contact with the first Mes. If the Nazir has
released his hold of the Mes, then even Rabah agrees that the Nazir is not
allowed to touch another Mes, since that will add to the Nazir's Tum'ah, in
the following way. A person who touched a Mes but is no longer touching it
has the status of a regular Av ha'Tum'ah, and he only makes someone else who
touches him into a Rishon l'Tum'ah. But if the person is still touching the
Mes, then whoever touches him becomes an Av ha'Tum'ah.
Both Rabah and Rav Yosef agree, therefore, that when a Nazir is no longer
touching a Mes, it is prohibited for him to touch another Mes.
This Isur of a Nazir to touch another Mes has practical ramifications
regarding the Isur of a Kohen to touch a Mes (as we find that the Gemara
compares the Isur of a Kohen to touch a Mes to the Isur of a Nazir). We know
that the Isur of Tum'as Kohanim applies even today. What are the Halachic
ramifications of this Gemara for a Kohen?
(a) The Rishonim rule like Rabah because of the principle that whenever
Rabah and Rav Yosef argue, the Halachah follows the view of Rabah (see Bava
Basra 114b). Since, in our Gemara, Rabah rules that a Nazir is Chayav for
becoming Tamei when he touches a second Mes while he is no longer touching
the first Mes, it follows that it should be prohibited for a Kohen to become
Tamei from a Mes (including Tum'as Ohel) unless he is still touching another
Mes. This is the ruling of the RAMBAM (Hilchos Nezirus 5:17, Hilchos Avel
TOSFOS (43a, DH me'Hacha) and the ROSH (Hilchos Tum'ah #6) add that it is
because of this that it has become customary to arrange for Kohanim a
separate section in a cemetery, at the edge of the cemetery. Even though it
is permitted for a male relative of a deceased Kohen to *enter* the cemetery
in order to bury his relative since he is already touching a Mes (which is
permitted for a Kohen to do for a close relative), nevertheless *after* the
burial the Kohen will have to become Tamei again by walking over other
graves in order to exit. Since at that time he is no longer touching a Mes,
he will be adding to his Tum'ah, which is prohibited. Consequently, we would
not be able to permit the male relative of a deceased Kohen to enter the
cemetery to bury the Mes. Therefore, a separate section for Kohanim is made
at the edge of the cemetery so that the relatives of the deceased Kohanim
will be able to exit the cemetery without having to walk over other graves.
(b) However, the ROSH here (42b, DH Kan) suggests another interpretation of
the entire Sugya. According to the Rosh, it is Rav Yosef who distinguishes
between a Nazir who is presently touching a Mes (Tum'ah b'Chiburin) and one
who is not touching a Mes (Tum'ah she'Lo b'Chiburin). Rabah, who says that a
Nazir does not transgress the Lav if he is already Tamei, means that even if
he is *not* touching the first Mes at the time he touches the second Mes, he
still does not transgress the Lav.
The Rosh (Hilchos Tum'ah, loc. cit.) quotes RABEINU TAM who learns the
Gemara in this way and rules like Rabah, that a Kohen does not transgress
the Lav even if he is not touching the first Mes at the time he touches the
second Mes (see Rabeinu Tam as cited by Tosfos in Shevuos 17a). The Rosh
adds that this Machlokes between Rabah and Rav Yosef appears to be a
Machlokes Tana'im in a Beraisa (Avel Rabasi 4:15).
Even according to this ruling, there are still prohibitions involved with a
Kohen touching a Mes while he is Tamei. First, the Rosh shows that the
Beraisa in Avel Rabasi prohibits a second Tum'ah *mid'Rabanan*, even
according to those who permit it mid'Oraisa. Second, it is clear from the
Beraisa that on the *following day*, it is Asur *mid'Oraisa* to touch
another Mes, since that will extend the Kohen's Tum'ah another day and
therefore it is considered to be adding to his Tum'ah.
The Rosh writes that according to this opinion, it is not necessary for the
Kohanim to have a separate burial section at the edge of the cemetery. Since
the Isur is only mid'Rabanan, in this case it is permitted for the Kohanim
to enter the cemetery to bury their relatives because of Kavod ha'Briyos,
even though doing so will require that the Kohen be Metamei himself in order
to exit after the burial.
(c) The RA'AVAD (Hilchos Nazir, loc. cit.) understands the Gemara like the
Rosh, that Rabah permits becoming Tamei a second time even when the Kohen is
no longer touching the first Mes, but he is even more lenient in his ruling.
He writes that since the Halachah is like Rabah, it is permitted for Kohanim
who are already Tamei to touch a Mes *l'Chatchilah* (there is not even an
Isur d'Rabanan), and even on *the day after* they become Tamei it is also
permitted for them to touch a Mes! The Ra'avad writes that this is why we
cannot obligate Kohanim nowadays to keep away from a Mes. (This is the way
REBBI AKIVA EIGER and others understand the Ra'avad. See, however, DAGUL
MERAVEVAH YD 372:2, and Insights to Yevamos 61:1:b.)