rather, when it is said here, “For them is the curse,” it means that they receive it as their recompense. When it is said, “Upon them,” the intention is to invoke a curse upon them. The two meanings are therefore distinct.
“Upon them” may also be intended as a statement of fact, meaning that the curse has fallen upon them. Thus the preposition “upon” changes the meaning conveyed by “for,” which denotes a particular association, although both expressions convey that those people are cursed.
His words, “Stipulate in their favour,” have a meaning distinct from “Stipulate against them.” How, then, can an expression be explained as meaning its opposite? Moreover, ʿĀʾishah had already stipulated this against them, saying: “If they wish, I will pay them the whole amount at once, and your rights of patronage will belong to me. But they refused.”
Furthermore, the rights of patronage belong to the one who sets a slave free without any need to stipulate this. Once he frees the slave, those rights belong to him, whether or not he stipulated this against the seller. This interpretation of the hadith would still suggest that the rights of patronage accrue to them only if she stipulates this, which is false. Anyone who reflects on the hadith will know with certainty that the Messenger did not intend this.
As for what the hadith actually indicates, they found it problematic on two counts. First, how could the Messenger command an invalid condition? Second, how could an invalid condition fail to invalidate the contract? A group of scholars offered a third answer, mentioned by Ahmad and others, namely that