aź-Źahabī, may Allah have mercy upon him in the Siyār al-A’lām an-Nubalā’ said:
He is the Qādhī, the fakhr (glory) of Islām, the syeikh of the syafi’ites, ‘abd al-Mahāsin ‘abd al-Wāhid bin Ismā’īl bin Ahmad bin Muhammad ar-Rūyānī al-Tabarī ash-Syāfi’ī.
His birth is at the end of 415 AH and he took fiqh in Bukhārā for a period of time. He heard from Abū Mansūr Muhammad bin ‘abd ar-Rahmān al-Tabarī, Abū Ghānim Ahmad Bin ‘Ālī al-Kurā’ī al-Marwazī, ‘abd as-Śamad bin Abū Naśr al-‘Āśimī al-Bukhārī, Abū Naśr Ahmad Bin Muhammad al-Balkhī, the sheikh of Islām Abū ‘Uthmān aś-Śābūnī, ‘abd Allāh Bin Ja’far al-Khabbāzī, Abū Hafś Bin Masrūr, Abū Bakr abd al-Malik Bin ‘abd al-‘Azīz and Abū ‘abd Allāh Muhammad bin Bayān al-Faqīh.
His travels were entirely in seeking fiqh and hadīth. He excelled in fiqh, gained mastery and researched, writing spectacular books.
Zāhir asy-Syahāmī, Ismā’īl Bin Muhammad al-Taimī, Abū Tāhir as-Silafī, Abū Rashīd Ismā’īl Bin Ghānim, Abū al-Futūh al-Tāie and many others narrated from him.
If the books of asy-Syāfi’ī were to be consumed by fire, I would surely dictate it from memory.
The book al-Bahr regarding the maźhab which is very long yet valuable in fawāid (benefits) is attributed to him. Other books are Manāśiś asy-Syāfi’ī, Hilyah al-Mu’min, and al-Kāfī.
He possesed very high dignity and rank yet is overabundant in modesty. He was accepted completely and very learned in fiqh. As-Silafī said:
It has reached us that he was dictating in Āmul and was murdered after concluding the gathering of imlā’ (dictating) due to ta’aśśub (fanaticism) in the religion. This occurred in Muharram.
He then said:
al-‘Imād Muhammad Bin Abū Sa’d who was the Śadr (Chief) of Ray in his time said: Abū al-Mahāsin is the Shafiite Qādhī of his time.
Ma’mar Bin al-Fākhir said:
He was killed in the Jāmi’ of Āmul on a Friday on the 11th of Muharram. The Malāhidah who were the Ismā’īliyah killed him. The Nizham al-Mulk had a lot of veneration for him.
I say: he was killed in 501 AH. Rūyān is a town (baldah) in the province of Tabaristan. As for Ray, it is a large city (Madinah) in which at-Rāzī is ascribed to.