If description were not sufficient for it, it would not be permissible for the rider to appoint someone else in his place, because he only knows that [the substitute] is like him due to their equality in characteristics. Thus, that which cannot be reached by characteristics is not known in its equality. Furthermore, because description is sufficient in sale, it is therefore sufficient in leasing, just like seeing is. Any disparity remaining after mentioning the apparent characteristics is minor and is overlooked, just like in a Salam sale.

Section: It is permissible to hire camels and pack animals for carrying loads. Allah the Exalted says: "And they carry your loads to a land you could not have reached except with great difficulty" (Surah an-Nahl: 7). The word "hamula" (with a damma on the ha) refers to the loads. "Hamula" (with a fatha on the ha) refers to that which is loaded. Allah the Exalted says: "And of the cattle, some for carrying loads and some for slaughter" (Surah al-An'am: 142). "Hamula" refers to the large ones, and "farsh" refers to the small ones. It is also said that "hamula" refers to camels and "farsh" refers to sheep, because they do not carry loads. There is no need for knowledge of the mount (hamula) itself because the purpose is to carry goods, not the animal that carries them, unlike riding; for the rider has a purpose in the mount regarding its ease, [its load-bearing capacity, and its speed]. If it happens that a purpose exists regarding the load-bearing animal—such as the item carried being something that is harmed by excessive movement, like fruit or glass, or if the path is such that it is difficult for some [animals] but not others—then it is appropriate to mention it in the lease. As for the loads, they must be known; if he does not know them, it is not permissible, because that varies greatly and the purpose regarding it differs. If he stipulates that it may carry whatever it wishes, the contract is void, because it is impossible to fulfill and could include things that would kill the animal. If he says, "Let it carry its capacity," this is also not permissible because it has no fixed standard. Knowledge is attained in two ways: observation, because it is...