or something similar, we say: “Produce evidence that the fire occurred,” or, “Produce evidence that the collapse occurred.”
If the principal claims that the property was not among what burned, then the agent’s statement is accepted, because he is a trustee.
“Whoever claims that Zayd appointed him as his agent to collect his due from Amr is not entitled to demand payment from him, even if Amr believes him; nor is Amr required to swear an oath if he considers him untruthful. If Amr pays him, and Zayd denies having appointed him as agent, Amr must swear an oath and is liable for it. If what was paid was a deposit, he may take it; but if it is destroyed, Zayd may hold either of them liable.”
His statement, “Whoever claims that Zayd appointed him as his agent to collect his due from Amr”: here, “appointment as agent” is a verbal noun attributed to its doer. That is, he claims that Zayd appointed him as his agent “to collect his due”—that is, Zayd’s due from Amr.
The case thus involves three parties: Zayd, who is the claimant; Amr, who is the defendant; and Abdullah, who is the agent. Abdullah comes to Amr and says, “Zayd appointed me as his agent to collect his due from you.” Amr replies, “You are an upright, religious, and scrupulous man, but I will not give it to you.” This is why the author says, “He is not entitled to demand payment from him, even if Amr believes him”—meaning that Amr is not obliged to hand over the due, even if he believes the one claiming agency, namely Abdullah.
Thus, Amr says to Abdullah, “I am not saying that you are lying. You are an upright man, and it is as though I can hear him appointing you as agent because of the trustworthiness and honesty I know in you. But I will not hand it over to you.” We say: he is not obliged to do so, because Zayd may deny having appointed him as agent and say, “I did not appoint him.” Even if Abdullah is truthful that Zayd did appoint him, Zayd himself may act wrongfully and deny the agency. If he says, “I did not appoint him,” Amr’s right is lost, and Amr may be made to pay the debt twice. For Zayd, who is entitled to the payment, will say to Amr, “My due never reached me, because I did not appoint Abdullah as my agent”; and he has that right.