against himself counts as decisive proof upon him, even if he is an unabashed sinner known for lying. Such a confession is not like a man’s testimony concerning someone else, for testimony against another is rejected when the witness is notorious for falsehood—so how could the claim of one who testifies about Allah Himself, saying that Allah has sent him, be accepted?
Accordingly, a self-confessor may have his admission accepted against his own person, yet any claim he makes about another is inadmissible. Likewise, a witness’s testimony can be accepted in a case where he is not a litigant, but his testimony is rejected in matters in which he has a personal stake.
By contrast, the person who says, “I am Allah’s Messenger,” cannot be believed in some of what he reports from Allah while being disbelieved in other parts. If he is lying in a single word, then he is not Allah’s messenger, and nothing he says may be cited as evidence. Even if the content of a statement were true in itself, the moment he attributes it to Allah—claiming that Allah commissioned and revealed it to him—he is not speaking truthfully if he has lied about Allah in a single word, for Allah does not send a liar.
Conversely, if he has not lied in even one word, it becomes obligatory to believe everything he conveys; selective belief—affirming some of what he transmits from Allah while rejecting the rest—is impossible, unlike the situation with a mere confessor or an ordinary witness.
Should the objector’s purpose be to show that the claimant contradicts himself, then such an argument would only prove that he is not a messenger—and that gains them nothing, especially since it has become evident that no contradiction exists. If, on the other hand, the aim is to bind Muslims by his words, we have already demonstrated in several ways that they are under no such obligation. This makes it clear that they are not permitted to use any part of Muhammad’s—peace and blessings be upon him—statements as proof, whether they profess to believe him or to deny him.