Abu Ishaq al-Isfara'ini was a renowned Sunni scholar, jurisconsult, legal theoretician, hadith expert, Qur'anic exegete, theologian and a specialist in the Arabic language.
[2] Abu Ishaq al-Isfarayini was born in Isfarayin, a town snuggled in the gateway to the northern mountains of Khorasan and divided from the main road linking from Bayhaq to Nishapur by a grass valley and a chain of hills.
His most famous students became world renowned of their time:[5][1][9][6][10] Al-Isfara'ini died in the Islamic month of Muharram in 418 AH (February 1027 CE), and was buried in Isfarayin.
Abu Ishaq wrote extensively on legal theory, Shafi'i substantive law, hadith and theology, but scholars believe he devoted a great deal of his attention in debating deviant sects such as attacking the Mu'tazila beliefs.
Later Shafi'i legal theorists such as Imam al-Haramayn al-Juwayni and Al-Ghazali have preserved Abu Ishaq's position on the issue of the epistemological yield of hadiths and the effect of consensus.