to the entire half, thus he would be selling that which is valid to sell and that which is not valid, and this would be one of the instances of breaking up a transaction (tafriq al-safqah), so it is not valid regarding the quarter that has not been taken into possession. As for whether it is valid regarding the portion taken into possession, there are two views.

Section: As for hawalah (transfer of debt), its meaning is that a person owes a buyer of food some food [due from a salam contract] or from a loan, similar to what he purchased, and he says to his creditor: "Go and take possession of the food that I have purchased for yourself." This is not permissible, because it is not permitted for him to take possession of it before he (the debtor) has taken possession of it himself. We have already mentioned the derivation of this in the section prior to this (19) issue.

Section: If a man has some food owed to him by another as a loan, it is not permissible for him to sell it to someone else before taking possession of it, because he is unable to hand it over. It is permissible to sell it to the person who owes it, according to the correct position in the madhhab, based on the hadith of Ibn Umar: "We used to sell camels at al-Baqi for dirhams, then we would take dinars in their place (20)." This is the school of al-Shafi'i. It has also been narrated that it is not valid, just as it is not valid in the case of salam. The first [view] is more appropriate. If he buys it from him for a commodity described in the liability (dhimmah) of a different genus, it is permissible, provided they do not separate (21) before taking possession, because it would be a sale of a debt for a debt. If he gives him a specific item for which mutual possession is stipulated, for example, if he gives him barley in exchange for wheat, it is permissible. It is not permissible to separate before taking possession. If he gives him a specific item for which mutual possession is not stipulated, separation before taking possession is permissible, as if he said: "I have sold you this barley for a hundred dirhams owed by you." It is also possible that it is not permissible, because the commodity sold is in the liability, so separation before taking possession is not permitted, like in the case of salam.

Section: If a man says to his creditor: "Sell me this on the condition that I settle your debt with it," and he does so,