Kitab al-Kharaj

Kitab al-Kharaj (Arabic: كتاب الخراج, lit. 'Book of Taxation') is an 8th-century Islamic legal treatise authored by Abu Yusuf, a Hanafi jurist and chief justice under the Abbasid Caliphate. Written at the request of Caliph Harun al-Rashid, it provides legal and administrative guidance on taxation, land revenue, and public finance in accordance with Islamic law. The book discusses principles of justice, fair taxation, and state responsibility toward citizens, outlining the rights and duties of both rulers and taxpayers and emphasizing public welfare and the prevention of oppression. Considered the magnum opus of Abu Yusuf, it foregrounds legal reasoning and includes his independent ijtihad, representing one of the earliest systematic treatments of Islamic fiscal policy. The author also cites numerous hadiths to support his arguments, making it an early example of Sunni hadith collection.