Why did the Rabanan not make the same Gezeirah in the case of a Ketanah
married to a Kohen? There, too, if we permit the Ketanah to eat Terumah,
people might mistakenly assume that when a Kohen who is a Katan marries a
Gedolah, the Gedolah may eat Terumah, which is certainly prohibited!
(a) RASHI (DH Gezeirah) answers that there is no such thing as a Katan
marrying a Gedolah. The Rabanan did not institute Kidushin at all for a
Katan, as the Gemara says on 112b.
This opinion of Rashi's is not accepted by all Rishonim. Others seem to hold
that a Katan may marry a Gedolah (and there is Kidushin d'Rabanan, despite
what the Gemara on 112b says), as we shall explain.
(b) TOSFOS (DH Shema Ya'achil) argues with Rashi's answer. Tosfos earlier
(62b, DH Samuch) points out that the Gemara praises a person who marries off
his "children" (i.e. *sons* and daughters) immediately before they reach
puberty. This clearly implies that the Rabanan *did* institute Kidushin for
a Katan (see also Tosfos 96b, DH Nasa). When the Gemara says that the
Rabanan did not institute Nisu'in for a Katan, it means that they did not
institute Nisu'in that has the full status of marriage as far as all of the
Halachos of marriage are concerned (such as the right of the husband to keep
the income of the wife). However, they did institute that a Katan is
permitted to marry, and is not considered to be living with an unmarried
woman and involved with Z'nus.
Why, then, according to Tosfos, did the Rabanan not make a Gezeirah
prohibiting a Ketanah who is married to a Kohen from eating Terumah, lest
people assume that a Gedolah married to a Katan who is a Kohen may also eat
Tosfos explains that a Katan is usually married off only close to adulthood.
Since there is not much time until he reaches adulthood, at which point his
Kidushin becomes a Kidushin d'Oraisa, the Rabanan did not deem it necessary
to make a Gezeirah lest a Gedolah married to a Katan who is a Kohen eat
Terumah in that short amount of time before he reaches adulthood.
(c) RABEINU YITZCHAK BAR'REBBI YEHUDAH, cited by the MAHARIK (Shoresh #32),
writes that the father of a Katan may accept Kidushin for his Katan son, and
the Kidushin is d'Oraisa, because of the principle of "Zachin l'Adam sh'Lo
b'Fanav" -- a person may acquire an asset for somebody else while not in his
presence. If the Kidushin of the Katan is d'Oraisa, then perhaps there is no
need to make a Gezeirah prohibiting the Ketanah from eating Terumah, because
when a Katan is married to a Gedolah, she may eat Terumah because the
Kidushin is d'Oraisa!
It is true that when it comes to acquiring property, we find that the Gemara
(Bava Metzia 72a, Kidushin 42a) says that one *may* be Mezakeh property to a
Katan, and some Rishonim (see RAN in Kidushin ibid., TOSFOS Sanhedrin 68b)
say that the Kinyan is even mid'Oraisa. However, we do not find that one can
acquire a *wife* for a Katan through Zechiyah (or even for a Gadol, for that
matter -- see Kidushin 45a and Rashi). The Acharonim deal at length with the
opinion of Rabeinu Yitzchak bar'Rebbi Yehudah. The MAHARIT (Teshuvos, Even
ha'Ezer 2:41) cites many proofs against this opinion, including our Gemara
(112b) that says that the Rabanan did not institute Nisu'in for a Katan,
implying that there certainly is no Kidushin d'Oraisa for a Katan. (See also
AVNEI MILUIM 1:1 who addresses some of the Maharit's questions on this
The Maharit concludes that even Rabeinu Yitzchak b'Rebbi Yehudah does not
mean to say that a Katan could become married, as a minor, with Kidushin
d'Oraisa through the father's ability to be "Zocheh she'Lo b'Fanav." Rather,
he means that the father may accept the money for the Kidushin while his son
is a Katan, in order for the Kidushin to take effect mid'Oraisa *when his
son grows up* through the money that was accepted on his behalf when he was
a Katan -- if his son expresses interest in the Kidushin at that point. (He
compares this to the Gemara in Kesuvos 11a that allows Beis Din to perform
Geirus for a Katan, which takes effect if he agrees to the Geirus when he
grows up.) Thus, there indeed is no Kidushin d'Oraisa for a Katan.
The RASHBA (109b) writes a very similar logic regarding a Ketanah. He says
that when a father accepts Kidushin for a Ketanah, as soon as she reaches
adulthood, the Kidushin becomes d'Oraisa, because the money that the father
accepted when she was a Ketanah was intended to be Mekadesh the daughter
from the moment that she becomes a Gedolah -- if she agrees to the Kidushin
at that point.