QUESTION: Rebbi Akiva and Rebbi Yishmael argue regarding the status of three
acts, whether those acts are voluntary (and are not Mitzvos) or whether
those acts are obligatory (and are Mitzvos). They argue regarding Kinuy for
a woman who is suspected of adultery, a Kohen becoming Tamei in order to
bury his close relatives, and the injunction not to free an Eved Kena'ani.
Rebbi Yishmael says that all three of these acts are voluntary, while Rebbi
Akiva maintains that they are obligatory.
TOSFOS here (see also RAMBAN, end of Shoresh Rishon of Sefer ha'Mitzvos)
asks how they could argue regarding whether these are Mitzvos or not. The
Gemara and Midrash tell us in many places that there are 613 ("Taryag")
Mitzvos. We should simply count the other Mitzvos in the Torah, and -- based
on the outcome of that count -- we should determine whether these three acts
are included in the 613 Mitzvos or not!
ANSWER: The MAHARSHAM quotes the SEFER MAYIM HA'CHAIM who explains that
Rebbi Yishmael -- who says that these three Mitzvos are voluntary -- is
following his own reasoning elsewhere. In Menachos (28a), the Mishnah says
that the 4 Tzitziyos on the four corners of a garment are Me'akev each
other, because they are all part of a single Mitzvah, and if one is missing,
then the entire Mitzvah is lacking. Rebbi Yishmael there argues and says
that the Tzitziyos are considered four separate Mitzvos and they are not
Me'akev each other. (The Gemara explains that according to Rebbi Yishmael,
if a person wears Tzitzis on only three corners of his garment, then each
one is considered to be the fulfillment of a Mitzvah, and if he walks into
Reshus ha'Rabim wearing the garment on Shabbos he is not Chayav. According
to the Tana Kama, he is Chayav because he is not fulfilling any Mitzvah
until he has all four Tzitziyos on his garment at one time.) Since Rebbi
Yishmael there adds three extra Mitzvos to the Torah by saying that each
Tzitzis is a Mitzvah in itself, he removed these three Mitzvos (Kinuy,
Tum'ah, and freeing one's Eved) from the count, since he considers them
Rebbi Akiva, who does include these three Mitzvos, holds like the Tana Kama
in Menachos there, who says that all of the Tzitzis are Me'akev the Mitzvah,
and one fulfills the Mitzvah only when he has four Tzitziyos on the four
corners of his garment.