Rav Shach in the Laws of Marriage chapter 1 brings the Tosphot R''id that "kinyan sudar" marriage by a handkerchief would be valid if it had a penny's worth in the handkerchief. Also it would valid if it was given over on condition to give later some money and later he in fact gives it.
Rav Shach explains there are two kinds of "kinyan sudar" one is exchange and the other is a special kind of exchange that exists only as a kind of way of completing a deal. Like nowadays a handshake would be in that kind of category. So the Tosphot Rid is including kinyan sudar when it is done as exchange with no further obligation to give anything more. And that would be a kind of monetary exchange. But not a when it is done specially as kinyan sudar which is its own category of kind of exchange.
The confusing issue for me here is that it seems that the Gemara is mainly interested in eliminating exchange, and does not really mention the kinyan sudar. I do not know if this is actually a good question, or just confusion on my part.
Just to be clear I will bring the basic Gemara. The Gemara Kidushin brings the mishna that a woman is acquired in three ways: money, document, sex;-- and that is meant to exclude exchange. You might have learned exchange from the field of Efron, since a field can be bought by exchange. So we now know not so, because a woman will not agree to be bought for less than a penny. And since exchange can be for less than a penny, therefore that whole kind of buying (exchange) is excluded--even if the exchange is done for more than a penny.
So you see right away what is bothering me. The Gemara is plainly interested in excluding the kind of acquisition that is specifically exchange, and does not even mention kinyan sudar. That is, it seems just the opposite of what we said up above. It looks as if a handkerchief as exchange would be not valid but perhaps as in fact a regular kinya sudar would be valid!
[The idea here is this: what causes a woman to be married? Being married is a sort of state of being that has with it obligations. When does that state exist? It is similar to when you buy a field. When makes it "bought"? In the West we understand that a document sometimes is just proof that some exchange happened, but sometimes it itself is what causes the exchange.]
Rav Shach explains there are two kinds of "kinyan sudar" one is exchange and the other is a special kind of exchange that exists only as a kind of way of completing a deal. Like nowadays a handshake would be in that kind of category. So the Tosphot Rid is including kinyan sudar when it is done as exchange with no further obligation to give anything more. And that would be a kind of monetary exchange. But not a when it is done specially as kinyan sudar which is its own category of kind of exchange.
The confusing issue for me here is that it seems that the Gemara is mainly interested in eliminating exchange, and does not really mention the kinyan sudar. I do not know if this is actually a good question, or just confusion on my part.
Just to be clear I will bring the basic Gemara. The Gemara Kidushin brings the mishna that a woman is acquired in three ways: money, document, sex;-- and that is meant to exclude exchange. You might have learned exchange from the field of Efron, since a field can be bought by exchange. So we now know not so, because a woman will not agree to be bought for less than a penny. And since exchange can be for less than a penny, therefore that whole kind of buying (exchange) is excluded--even if the exchange is done for more than a penny.
So you see right away what is bothering me. The Gemara is plainly interested in excluding the kind of acquisition that is specifically exchange, and does not even mention kinyan sudar. That is, it seems just the opposite of what we said up above. It looks as if a handkerchief as exchange would be not valid but perhaps as in fact a regular kinya sudar would be valid!
[The idea here is this: what causes a woman to be married? Being married is a sort of state of being that has with it obligations. When does that state exist? It is similar to when you buy a field. When makes it "bought"? In the West we understand that a document sometimes is just proof that some exchange happened, but sometimes it itself is what causes the exchange.]
