Kitab al-Kharaj (The Book of the Land Tax)
The best-known book of this title, by the judge Abu Yusuf Yaqub ibn Ibrahim (d. 182 AH). He wrote it at the request of Harun al-Rashid on the rules of the land tax, tithes, poll tax and zakat and the revenues of the treasury. It is a basic source for the financial system of the early Abbasid period.
Abu Yusuf (Yaqub ibn Ibrahim)