due to compensation or a defect in it. If this occurs by coincidence, it does not prevent validity, just as if that happened in a sale, and as if one entered into a forward sale (salam) for a female slave in exchange for another described by the same attributes, and then returned it specifically upon the arrival of the deadline. And if it is established that the loan is weak and does not permit sexual intercourse, it does not prevent it in the case of female slaves, like a sale during the option period. The absence of any scholar who differentiates is of no consequence, as is known in its proper places. And the absence of reports regarding it is not a proof; for the loaning of most animals has not been reported, yet it is permissible.

Section: If one borrows dirhams or dinars of unknown weight, it is not permissible; because the loan in them necessitates the return of the equivalent, and if the equivalent is not known, repayment is impossible. Likewise, if one borrows a measurable or weighable item by estimation (juzaf), it is not permissible; for the same reason. And if one determines it with a specific measuring tool, or a specific weight, not known to the general public, it is not permissible; because one is not secure from the loss of that, so the return of the equivalent becomes impossible, thus it resembles a forward sale (salam) in such a case. Imam Ahmad said, regarding water between people who have turns at designated days, if some of them needed to draw water outside of their turn, so they borrowed from another's turn to return its replacement to him on the day of his turn: There is no harm in it. But if it was not limited, I would dislike it. He disliked it if it were not limited; because it is not possible for him to return its equivalent. If the dirhams are transacted by number, he borrows by number and returns by number. If he borrows by weight, he returns by weight. This is the opinion of al-Hasan, Ibn Sirin, and al-Awza'i. Ayyub borrowed dirhams from Hammad ibn Zayd in Mecca by number and gave them to him in Basra by number, because he paid him the equivalent of what he borrowed in that which people use for transactions, so it is similar to if they were transacting them by weight, in which case he would return by weight.

Section: It is obligatory to return the equivalent in measurable and weighable items. We do not know of any disagreement regarding this. Ibn al-Mundhir said: All those we remember from the scholars have agreed that whoever gives a loan of that which is permissible to be loaned, and its equivalent is returned to him, that this is permissible and the lender may accept that. This is because measurable and weighable items are guaranteed in cases of usurpation and destruction by their equivalent. Thus it is the same here. As for non-measurable and non-weighable items, there are two opinions regarding it; one is that it is obligatory to return its value on the day of the loan; because it has no equivalent, so he guarantees it by its value, like in the case of destruction and usurpation. The second is that it is obligatory to return its equivalent;