1. two people agree on a deal with words only, no kinyan, nothing signed. the gemara in bava metzia 49a says that without a formal act of acquisition the deal did not close, but one who reneges on his commitment, the sages are displeased with him, and it invokes the mi shepara: He who exacted payment from the generation of the flood will exact payment from whoever does not stand by his statement. so legally either side can walk, but morally not? where exactly is the line between not closed and not allowed to walk away?
2. the concrete case: a deal agreed by text message for five thousand dollars, the seller turns away other buyers, and then the buyer finds it cheaper somewhere else and cancels. is that fully allowed because there was no kinyan, or is it mechusar amanah, acting without trustworthiness? does it matter how far the words went, a plain yes versus fully spelled out terms?
3. and what changes the picture: a deposit already paid, a handshake, a public commitment, or the other side relied on the deal and lost money because of it? at what point does backing out become a real issur and not just bad manners?
bottom line: when is a person halachically free to walk away from a verbal deal, and when is he not?
Thank you Rabbi, thank you very much.
There are several different levels here, and a lot depends on what people in that particular market understand to mean “the deal is done.”
First, mere words ordinarily do not create a formal kinyan. But that does not mean a person should casually give his word and then walk away. If two people clearly agreed on the item and the price, and in that type of transaction everyone understands “deal” to mean a final commitment, backing out simply because you found something cheaper or received a better offer is inappropriate and can be mechusar amanah. See Bava Metzia 49a.
Mi shepara is a different category. Classically, it applies where money has already been paid for movable property but the Torah kinyan has not yet been completed. The sale can technically still be reversed, but the person who backs out receives the severe mi shepara declaration.
Then there is situmta.
The Gemara in Bava Metzia 74a says:
האי סיטומתא קניא
A customary commercial act can create a kinyan. The Gemara concludes that where the local custom is that the act actually completes the sale:
ובאתרא דנהיגו למקני ממש קנו
If that is the accepted commercial practice, it works as an actual kinyan.
Shulchan Aruch, Choshen Mishpat 201, develops this very clearly. Siman 201 should really be read as a whole. It says that if merchants have a recognized way of finalizing transactions, that customary act can be binding. It specifically mentions giving a small coin, shaking hands, and in a place where merchants customarily do so, handing over the key.
So a handshake is not automatically just a polite gesture. If, in a particular industry, shaking hands means the transaction is completed, then the handshake itself can be a kinyan through situmta. At least traditionally, the diamond industry is a classic example where deals were commonly finaliz
e, or by the recognized words and customs of that trade. In that environment, the custom itself gives the act halachic force.
The same concept can apply to handing over keys. If, in a particular type of sale and according to the accepted practice there, delivery of the keys is understood to complete the purchase, that act can have the force of a kinyan.
That is why local custom matters so much.
For example, if I am selling a car for $20,000, you test-drove it, checked the Carfax, we settled all the terms, and we shake hands or exchange a message saying “done deal,” then if that is understood in that environment as final, neither side should simply back out because a better offer appeared.
But sometimes what sounds like an agreement is still clearly conditional.
Many years ago I was selling a house. We had agreed upon a price and the lawyers were already exchanging contract documents, but the buyer had not yet done his inspection. Before the inspection, someone else offered me substantially more money. I asked my father whether I could take the second offer.
He said yes.
His reasoning was simple. The first deal was not actually finished. The buyer still had the right to inspect the house and then say, “I found a problem, I want a lower price,” or walk away entirely. If he still had that right, then I was not yet locked into the transaction either.
That illustrates the principle very well. You have to look at what “done” means in that kind of transaction.
So the bottom line is:
If the deal is still genuinely conditional, either side can usually walk away.
If the negotiations are finished and a person gave his word, backing out merely for a better price can be mechusar amanah.
If money has been paid in the classic movable-property case, mi shepara may apply.
And if there has been an effective kinyan, including a recognized situmta under the commercial custom of that market, then the deal itself is binding.