id ▁Revolution ▁in ▁ 7 5 0 . ▁In ▁ 7 6 2 ▁he ▁took ▁part ▁in ▁the ▁rising ▁led ▁by ▁I bra him ▁I bn ▁Ab dal lah , ▁the ▁Al id , ▁called ▁" The ▁P ure ▁Soul ", ▁against ▁the ▁cal i ph ▁al - M ans ur , ▁and ▁after ▁the ▁defeat ▁and ▁death ▁of ▁I bra him ▁was ▁cast ▁into ▁prison . ▁Al - M ans ur , ▁however , ▁p ardon ed ▁him ▁on ▁the ▁inter cess ion ▁of ▁his ▁fellow ▁tribes man ▁Mus ay y ab ▁ibn ▁Zu h air ▁of ▁D ab ba , ▁and ▁appointed ▁him ▁the ▁instruct or ▁in ▁literature ▁of ▁his ▁son , ▁afterwards ▁the ▁cal i ph ▁al - M ah di . ▁It ▁was ▁for ▁this ▁prince ▁that , ▁at ▁al - M ans ur ' s ▁inst ig ation , ▁al - M uf add al ▁compiled ▁the ▁M uf add ali y at . ▁ ▁Al - M uf add al ' s ▁exact ▁date ▁of ▁death ▁has ▁proved ▁difficult ▁to ▁determine . ▁The ▁Encyclopedia ▁of ▁Arab ic ▁Liter ature ▁states ▁that ▁he ▁died ▁some ▁time ▁around ▁the ▁year ▁ 7 8 0 , ▁though ▁the ▁longer ▁window ▁between ▁ 7 8 1 ▁and ▁ 7 8 7 ▁has ▁been ▁claimed ▁as ▁well . ▁ ▁Work ▁Al - M uf add al ▁was ▁a ▁careful ▁and ▁trust worth y ▁collect or ▁both ▁of ▁texts ▁and ▁trad itions , ▁and ▁is ▁pra ised ▁by ▁all ▁authorities ▁on ▁Arab ian