and would say, in justification for not reading it: “It is a problem in arithmetic, so there is no point in occupying oneself with it.” But matters are not as they claimed. Its difficulty lies in the jurisprudence, not the arithmetic. Whoever understands its legal aspects will find nothing confusing in its arithmetic, nor in that of the two problems that follow it in the chapter: where the creditor stipulates that every pair of them guarantees the entire sum, or that every group of three guarantees the entire sum. This is why I have taken care to explain and clarify it. Success rests with Allah, who has no partner, and none besides Him is worthy of worship.
Section
At the end of the problem in the book concerning three men who bought an item on condition that each guaranteed what his fellow owed, there is a passage whose difficulty requires clarification. The unproblematic portion reads:
He said: “I asked Ibn al-Qāsim about three men who bought an item from a man, who had it recorded against them that he could recover his due from whichever of them he chose, and that each guaranteed what his fellow owed. One of the three then died, and his heirs claimed that he had paid the entire sum to the seller of the item, producing one witness.”
He said: “They swear an oath in support of their witness’s testimony and are discharged from liability. They may then recover from the two surviving partners what the deceased paid on their behalf.”
As for the passage beginning, “I said: What if the heirs refuse to swear?” through to the end of his statement, it presents a difficulty. Its explanation is that, if the heirs decline to swear an oath in support of their witness’s testimony, the deceased must have been either solvent or insolvent. If he was solvent, there are three possibilities:
The first is that the two partners affirm the heirs’ claim that the deceased paid the seller the entire amount out of his own funds, on his own behalf and theirs, intending to recover their respective shares from them.
The second is that they say: “All of that came from our funds, and we had appointed him as our agent for that purpose.”
The third is that they say: “He paid that to the seller out of his own funds—and ours, since we had already given him the share of it falling to him and appointed him to pay it on our behalf.”