Mezue ahịrịokwu na-esonụ: Fadl malitere ọrụ ya n'oge ọchịchị Harun al-Rashid (r. 786<unk>809) dị ka onye na-ejide Harthama ibn A'yan, n'oge ahụ onye isi ndị nche caliphal. Nkà nchịkwa ya mere ka Harun mara ya, bụ́ onye họpụtara ya odeakwụkwọ na "diwan al-kharaj" (ụlọ ọrụ "Ụtụ Isi Ala"). N'oge
agha obodo nke sochiri ọnwụ Harun, Fadl lara ezumike nká n'ala ya dị na Iraq. Ọ bụ ebe ahụ ka Abu Ishaq, nwanne nwoke nke Caliph al-Ma'mun (r. 813 <unk> 833) na Caliph al-Mu'tasim n'ọdịnihu, onye jiri ihe ọmụma ọkachamara ya banyere ụtụ isi na ọrụ ugbo kpọrọ ihe. N'afọ 828, Abu Ishaq kpọọrọ ya gaa Ijipt wee họpụta ya ka ọ bụrụ onye isi nke "diwan al-kharaj".