His full name was Abul-Qasim Hussein ibn Muhammad Al-Raghib Al-Isfahani (often written as Asbahani), also known as Ibn Al-Mufaddal. He was of Persian descent, born in Isfahan (modern day Iran). He lived in around 502 AH (eleventh-century A.D.) and was a scholar of Qur’anic exegesis and the Arabic language.
Imam Al-Dhahabi (in his Siyaar A’laam Al-Nubala’) says about him:
العلامة الماهر ، المحقق الباهر أبو القاسم ; الحسين بن محمد [ ص: 121 ] بن المفضل الأصبهاني ، الملقب بالراغب ، صاحب التصانيف .
“The profound Allamah, outstanding Muhaqqiq, Abu Al-Qassim; Al-Hussein ibn Muhammad ibn Al-Mufaddal Al-Asbahani, known as Al-Raghib …”
Imam Al-Isfahani is he author of he all time classic and famous Al-Mufradat fi Gharib al-Quran (Arabic: المفردات في غريب القرآن), a dictionary specialised for difficult Qur’anic terms. This books is the best of it’s field and fills the bookshelves of every good Muslim library around the world.
Al-Isfahani’s theological stance seems to have been close to that of the Ash’ari school. In one of his works entitled al-I’tiqadat, Al-Isfahani attacks both the Mu’tazila and the Shi’a, refuting their core beliefs. He also declared the Shia misguided for their Imamah belief of so-called 12 infallible Imams. In his book “Al-Mufradat fi Gharib Al-Qur’an” he also refuted the Shia, Mu’tazilah, Jabriyyah and Qadriyyah with textual and logical evidences.
Al-Isfahani (like most Pre-Safavid Persian scholars) was a master of the Arabic language, born and raised in what is known as Isfahan today. In our age, in post-Safavid Rafidi Shi’i Iran it is almost impossible to even dream of a Shia authority hailing from Qom or Isfahan and being known for proficiency in the Qur’an or the Arabic language, however in pre-Safavid (Shiite) Persia it was the norm amongst the scholars.