Muwatta Malik, Book 39, Hadith 7 (USC-MSA) ⓘ

Malik said, "The best of what is said about a man who buys the mukatab of a man is that if the man wrote the slave's kitaba for dinars or dirhams, he does not sell him unless it is for merchandise which is paid immediately and not deferred, because if it is deferred, it would be a debt for a debt. A debt for a debt is forbidden." He said, "If the master gives a mukatab his kitaba for certain merchandise of camels, cattle, sheep, or slaves, it is more correct that the buyer buy him for gold, silver, or different goods than the ones his master wrote the kitaba for, and that must be paid immediately, not deferred." Malik said, "The best of what I have heard about a mukatab when he is sold is that he is more entitled to buy his kitaba than the one who buys him if he can pay his master the price for which he was sold in cash. That is because his buying himself is his freedom, and freedom has priority over what bequests accompany it. If one of those who have written the kitaba for the mukatab sells his portion of him, so that a half, a third, a fourth, or whatever share of the mukatab is sold, the mukatab does not have the right of pre-emption in what is sold of him. That is because it is like the severance of a partner, and a partner can only make a settlement for a partner of the one who is mukatab with the permission of his partners because what is sold of him does not give him complete rights as a free man and his property is barred from him, and by buying part of himself, it is feared that he will become incapable of completing payment because of what he had to spend. That is not like the mukatab buying himself completely unless whoever has some of the kitaba remaining due to him gives him permission. If they give him permission, he is more entitled to what is sold of him." Malik said, "Selling one of the instalments of a mukatab is not halal. That is because it Is an uncertain transaction. If the mukatab cannot pay it, what he owes is nullified. If he dies or goes bankrupt and he owes debts to people, then the person who bought his instalment does not take any of his portion with the creditors. The person who buys one of the instalments of the mukatab is in the position of the master of the mukatab. The master of the mukatab does not have a share with the creditors of the mukatab for what he is owed of the kitaba of his slave. It is also like that with the kharaj, (a set amount deducted daily from the slave against his earnings), which accumulates for a master from the earnings of his slave. The creditors of his slave do not allow him a share for what has accumulated for him from those deductions." Malik said, "There is no harm in a mukatab paying off his kitaba with coin or merchandise other than the merchandise for which he wrote his kitaba if it is identical with it, on time (for the instalment) or delayed. " Malik said that if a mukatab died and left an umm walad and small children by her or by someone else and they could not work and it was feared that they would be unable to fulfil their kitaba, the umm walad of the father was sold if her price would pay all the kitaba for them, whether or not she was their mother. They were paid for and set free because their father did not forbid her sale if he feared that he would be unable to complete his kitaba. If her price would not pay for them and neither she nor they could work, they all reverted to being slaves of the master. Malik said, "What is done among us in the case of a person who buys the kitaba of a mukatab, and then the mukatab dies before he has paid his kitaba, is that the person who bought the kitaba inherits from him. If, rather than dying, the mukatab cannot pay, the buyer has his person. If the mukatab pays his kitaba to the person who bought him and he is freed, his wala' goes to the person who wrote the kitaba and the person who bought his kitaba does not have any of it."