Diwan (the state register: the office books of troops, taxes, judges and governors)

A diwan is a register in which names or documents are entered, and which keeps what concerns the state's business, funds and officials. ¹ Umar ibn al-Khattab was the first to set one up in Islam. ²

The Malikis allow the imam to keep a diwan, a register of the troops' names and pay. ² The Shafi'is recommend the troops' register in their accepted view, and the Hanbalis say the imam should keep one to fix the fighters and their allowances. ^{2 3}

For the army: enrolment and pay; a body of troops that refuses to fight when called loses its allowance, while a sick or insane man whose condition may improve stays on the register. ³ For the business of revenue: each district is described with its land, whether it pays tithe or land-tax; the non-Muslims and their poll tax are recorded; mines and frontier towns are noted. ^{3 4} For the officials: appointment, dismissal and stipends, with the conditions of a valid appointment as to district, duty and term. ^{4 5} The clerk of the diwan must be trustworthy and capable; he keeps the rules, collects dues, and hears complaints. ^{5 7 8}

A judge's diwan holds people's documents, records and minutes; a new judge takes it first and the predecessor hands it over. ⁶ The diwan of letters was set up when the language decayed, so that the rulers' letters could be written in eloquent words. ⁶