a governor, and the celestial sphere without a director; then He rose and returned to the state He had been in, so that—according to their claim—Allah, exalted be He, became temporal while the temporal turned eternal, and Allah, exalted be He, was carried in Mary’s womb. They predominate in the districts of Egypt, throughout Nubia and Abyssinia, and among the kings of those two nations.

I say: The people best informed about their doctrines are those who once counted among their own scholars but embraced Islam with clear insight after long familiarity with their books and teachings—such as al-Hasan ibn Ayyub. He wrote a letter to his brother ʿAli ibn Ayyub in which he recounted the reason for his conversion and set forth the proofs of the invalidity of the Christian faith and the truth of Islam.

In that letter to his brother—who had written asking about the cause of his conversion—and after recording his opening address, he said:

“Then let me inform you—may Allah guide you—that the first stirrings of doubt that entered my heart regarding the creed I had followed, and the revulsion I felt toward professing it, began more than …”