Imam al-Khatib Abu Abdullah's book Durrat al-Tanzil and Ghurrat al-Taweel is the oldest work that we know of that was compiled independently, dedicated to guiding what is similar, similar, or repeated in the words and verses of the Qur'an. Scholars of this matter, ancient and modern, have praised it and taken an example to follow, although contemporaries have only seen it through an unverified print, which is full of errors, errors, and omissions.