Al-Ḍiyāʾ said: He—may Allah have mercy on him—was an imam in Qur’anic exegesis (1), in hadith and its problematic texts, an imam in jurisprudence, indeed the unrivalled scholar of his age in that discipline; an imam in the science of legal disagreement, unmatched in the laws of inheritance; an imam in legal theory, an imam in grammar, arithmetic, and the movements of the planets and the lunar mansions.

I heard Dāwūd ibn Ṣāliḥ, the Qur’an-reciter, say: I heard Ibn al-Mannī declare—while Imam al-Muwaffaq was present—“If this young man were to leave Baghdad, the city would be in need of him.”

I heard al-Bahāʾ ʿAbd al-Raḥmān say: Our shaykh Ibn al-Mannī used to tell al-Muwaffaq, “Should you depart from Baghdad, it will find no one to replace you.”

I heard Muḥammad ibn Maḥmūd al-Iṣfahānī say, “No one has ever seen the like of Shaykh al-Muwaffaq.”

I heard the mufti Abū ʿUbayd Allah ʿUthmān ibn ʿAbd al-Raḥmān al-Shāfiʿī say about al-Muwaffaq, “I have never seen anyone comparable to him; he was divinely aided in his legal verdicts.”

I heard the mufti Abū Bakr Muḥammad ibn Maʿālī ibn Ghunayma say, “In our time I know of no one who has reached the rank of independent legal reasoning (ijtihād) except al-Muwaffaq.”

I heard the ḥāfiẓ Abū ʿAbd Allah al-Yūnīnī say: “With respect to what I have observed of the state of our shaykh and master, Muwaffaq al-Dīn, up to now I do not believe that anyone I have met has attained the same perfection in knowledge and in the praiseworthy qualities that lead to true distinction. He was complete in both outward form and inner substance—beauty, beneficence, forbearance, nobility, mastery of diverse sciences, and noble character. I witnessed from him things that even the greatest…"