The first is that the principle in a sale is the absence of ownership by each of the two parties of what has been transferred to them, while the principle in a mukatab (contracted slave) and his earnings is that they belong to his master, so the word is the word of the master regarding it. The second is that taking an oath against each other (tahaluf) in a sale is beneficial, whereas there is no benefit in taking such an oath in a kitabah contract; for the result achieved thereby is attained by the oath of the master alone. The explanation for this is that the result of the tahaluf is the annulment of the kitabah and the return of the slave to servitude, if he is not satisfied with what his master has sworn to, and this is achieved by making the word the word of the master with his oath. Thus, the tahaluf is not legislated when there is no benefit in it. We have given precedence to the word of the denier in other situations because the original principle is with him, whereas here, the original principle is with the master, because the original state is his ownership of the slave and his earnings. Once this is established, whenever the master swears, the kitabah is established at two thousand, just as if they had agreed upon it, whether their disagreement was before the emancipation or after it—such as if he pays him two thousand and is emancipated, then the mukatab claims that one of them was for the kitabah and the other was a deposit, while the master says: "Rather, both of them are kitabah money." Whoever advocates for the tahaluf says: If they take an oath against each other, each of them has the right to annul the kitabah unless he is satisfied with the word of his companion. If the tahaluf is after emancipation in the scenario we described, freedom is not revoked, because it cannot be revoked after it has been achieved, nor can servitude be restored after its removal. However, the master seeks recourse for its value and returns to him what he had paid him; if it is of the same genus, they offset it by the amount of the lesser of the two, and the one with the excess takes his excess.

Section: If they disagree on the performance of the installments, and the mukatab says: "I have paid and attained freedom," and the master denies it, the word is the word of the master with his oath, because he is a denier, and the word is the word of the denier with his oath. If they disagree on whether he has released him from the kitabah property or a part of it, the word is the word of the master with his oath for the same reason.

Section: If he enters into a kitabah contract with two slaves and receives payment from one of them but does not know from which of them he received it, the analogy of the school of thought is that lots should be cast between them; whichever one the lot falls to is emancipated, and the other remains in servitude, just as if he had emancipated one of his slaves and forgotten which one. If the other claims against him that he had paid, then the oath is upon him that he did not pay