What is "al-zamakhshari"

Abu al-Qasim Mahmud ibn Umar al-Zamakhshari, known widely as al-Zamakhshari (in ), also called Jar Allah ( Arabic for "God's neighbour") (18 March 1075 – 12 June 1144), was a medieval Muslim scholar of Persian origin, who subscribed to the Muʿtazilite theological doctrine, who was born in Khwarezmia, but lived most of his life in Bukhara, Samarkand, and Baghdad. He was a great authority on the Arabic language as well as a rationalist theologian.