From where do we get this notion that kiddushin works the same way as hekdesh? All we saw on Daf 2b is that since marriage and hekdesh have a similar result (in that they are assur to everyone else), the chachamim called marriage "kiddushin". It seems illogical that the chachamim would create a new mechanism of marriage for no apparent reason.
Tzvi Hertzberg, New York, USA
Chazal did not create a new mechanism of marriage but it all depends on the words the husband uses. We see this from what Tosfos writes at the end that if he would say "Me'ureses" or a different Lashon other than "Mekudeshes," the Kedushah would not spread throughout all of her. The reason is that it is only when he uses a form of the word "Kidushin" that the husband shows that he wants it to work like Hekdesh.
According to this, when the Gemara (2b) says that it is called "Kidushin" because she is forbidden to everyone like Hekdesh, this applies to every case of Kidushin -- even one in which the husband uses the word "Me'ureses," etc. If he was particular to use the word "Mekudeshes," then this adds an extra dimension that the Kedushah spreads throughout her like Hekdesh.
Kol Tuv,
Dovid Bloom
I found that Rav Elchanan Wasserman zt'l Hy'd, in Kovetz Shi'urim Kidushin #53, explains this further. He asks what difference does it make what words the husband used to marry her? Since Kidushin always means that the wife is forbidden like Hekdesh, how is it possible to say that there are two different kinds of married women in the Torah?
1. Rav Elchanan answers that there are two aspects involved in every Kidushin: (a) a "Kinyan" is made -- the acquisition that the husband attains in his wife, so to speak, and (b) an "Isur" is created -- the wife now becomes forbidden to every other man in the world. When the Gemara states that Kidushin is similar to Hekdesh, this only refers to the Isur involved, not to the Kinyan. However, generally speaking, when the husband creates a Kinyan, the Isur automatically follows in its wake, or alternatively when he creates an Isur, the Kinyan follows as a result.
2. The difference is now as follows. If he says, "Harei At Mekudeshes," this creates an Isur like Hekdesh. If he says that only half of her is Mekudeshes, the Kedushah automatically spreads to the second half, just like Hekdesh, and the Kinyan automatically follows. However, if he says, "At Ishti" or "Harei At Me'ureses," since he did not use a form of the word "Kidushin," his statement creates only a Kinyan. In a normal case, where he said that all of her will be Me'ureses, since he acquires a Kinyan in all of her, the Kedushah follows as a result of the Kinyan. However, if he says that half of her is Me'ureses, his statement creates only a Kinyan in half of her. Since a Kinyan cannot spread to the other half (because it is only Kedushah that can spread), the Kinyan gets "stuck" and cannot spread further and she is not Mekudeshes at all.
3. Accordingly, Chazal did not create a new mechanism of marriage but rather they said that when the husband uses a phrase associated with the Kedushah of Kidushin, he creates an Isur on the wife. If this is an Isur of Kidushin, it follows that it is logical that it should work the same way as the Isur of Kedushah of Korbanos.
Kol Tuv,
Dovid Bloom