Allah SWT describes in the Quran as the 'guidance to mankind, and the criterion (of right and wrong)' (2:185). Islamic scholars have therefore sought to explain the sciences associated with correctly understanding the revelation. This discipline has come to be known as 'Ulum al-Qur'an, or 'Sciences of the Qur'an', and includes many subjects, such as the nature and order of revelation, explanations of the types of expressions used in the revelation and how the sacred text is to be correctly recited. Imam Jalal ad-Din as-Suyuti wrote one of the leading comprehensive manuals on 'Ulum al-Qur'an, entitled Al-Itqan fi 'Ulum al-Qur'an. The text here translated is a summary by Salah ad-Din Arqahudan of many major topics covered in the Itqan.