As for the first argument, namely his statement:

“If prophethood is established by the occurrence of a miracle, it is known that there is a Sender who sent the messenger, since establishing the message necessarily entails establishing the Sender,”

this requires an unstated premise. His statement that knowledge of the messenger entails knowledge of the Sender is correct, for knowledge of a relation necessarily entails knowledge of both terms of that relation.

However, an objector may say to him: A miracle does not establish messengership until the existence of the Creator is known. Only then is the messenger’s truthfulness known, either because a miracle serves as an attestation, something recognized as self-evident in ordinary experience; or because, if a miracle did not indicate truthfulness, this would entail the Lord’s inability to provide a means of attesting the messenger’s truthfulness; or because affirming a liar is evil, and He is far exalted above doing evil. There are other such methods adopted by those practitioners of rational inquiry who maintain that a messenger’s truthfulness can be known only through a miracle.

The first two methods are those of al-Ash‘arī, his followers, and those who agreed with them, such as Judge Abū Ya‘lā and others like him. The second is the method of the Mu‘tazilites and those who agreed with them, such as Abū al-Khattāb and others like him.

Those who maintain that a messenger’s truthfulness can be known through means other than miracles have no need of this. The matter has been discussed at length in its proper place.

The point here is that the assertion:

“Those who affirm prophethood attain knowledge of Allah through the establishment of prophethood, without inquiry into rational proofs or drawing inferences from them. We do not deny the validity of rational inquiry, nor do we deny that knowledge may be attained through it. Our disagreement concerns only this question: Can knowledge be attained by other means?”

requires an explanation of how those who affirm prophethood attain that knowledge.

Here, the judge has followed the approach of al-Khattābī, whose words we have already transcribed,