Rather, such people were astray and ignorant, whereas the speech of the prophets is true beyond doubt. For that reason you will not find, in anything the Messiah said—or any other prophet for that matter—one word that supports their doctrines of the Trinity, the hypostases, the hypostatic union, and the other notions they invented without revelation or rational proof. On the contrary, they have put forward statements that run counter to both scripture and sound reason.

Al-Ḥasan ibn Ayyūb went on to say:

We have found the Christians known as the Nestorians differing from the Jacobites and the Melkites. The Nestorians claim there are two persons who share one will, and that the two natures have united so as to become, in one respect, a single reality. Yet they then fall back on virtually the same assertion as the others when they say that Mary gave birth to the Messiah. If she indeed bore the Messiah, they are forced to admit that she gave birth to the two united elements—the divinity and the humanity.

In the end their position amounts to the creed of the Jacobites, except that they have chosen ornate phrases, tailored to mislead the listener, and have not stated the doctrine as bluntly as the Jacobites do. For whoever is "united" with something must be mixed and fused with it until both become one entity. They further buttress their view by insisting that the humanity, once joined to the divinity, has never been separated from it. But whatever never parts from another must accompany it in all its various conditions of harm and benefit, good and evil, need and plenty.

He added:

As for their claim that Mary bore the Messiah only "with respect to his humanity," that is a sophism. How can a child be born already united with—and inseparable from—something else that itself was not born? How can this be when they maintain that he has never been apart from it at all? And is it sound—