If revenge is prohibited, how can there be business contracts?

Question

The Rambam brings this down in his discussion of the negative commandment of revenge :

In the words of the Sifra, "How far does the prohibition against taking revenge go? If a person requests, 'Lend me your sickle,' and the other won't lend it; and tomorrow [the latter] requests, 'Lend me your ax,' and he answers, 'I won't lend to you just as you didn't lend me your sickle.' In this case the Torah says, 'Do not take revenge.'"

But consider this scenario : two people A and B draft a business contract, A will deliver a shipment of axes to B by a certain date, and upon receipt B will deliver a shipment of sickles to A. When the deadline passes and A fails to deliver, B says "You didn't fulfill your part of the deal, so I won't fulfill mine".

So we have :

• "I won't lend to you just as you didn't lend me your sickle" - Forbidden because of revenge
• "I won't fulfill my part of the deal, just as you didn't fulfill yours" - (seemingly) Permitted because it's just a commonplace business dealing

But how and why are these two cases intrinsically different?

Answer 1

Perhaps this category of (prohibited) action of revenge is when one avoids doing something that benefits another person, which one would ordinarily do, because of a grudge or negative deed done by that other person. So in the example you give, if Ploni asks his friend Yosef to lend him his axe, ordinarily Yosef would lend his axe to a friend. In that case, Yosef is not allowed to change that favorable behavior based on some act that Ploni performed in the past (failure to loan a sickle); that would be issur revenge.

Similarly, Yosef would not, ordinarily, punch Ploni in the nose. If Ploni has just rudely stepped on Yosef's foot, Yosef is still forbidden to punch him in the nose; to do so would be taking revenge. But the Rambam would not need to mention that case, because it involves a positive action that Yosef is forbidden to do in the first place.

Here is the intrinsic difference between your two cases (the second being the incomplete business transaction):

Yosef would not ordinarily, out of the blue, deliver a load of his own axes as a gift a casual friend. That sort of action would never happen absent some sort of incentive (for example, Ploni sending Yosef a box of sickles). Therefore, the type of revenge that the Rambam forbids here doesn't apply in the case of such a transaction.