Secrets of Repetition in the Qur'an by Mahmoud bin Hamza Al-Kirmani

Kermani defined his approach in his book, saying: This is a book in which I mention the similar verses that were repeated in the Qur'an and whose wording is consistent, but some of them contained an addition or a deletion, or a precedence or a delay, or a substitution of a letter for a letter, or other than that, with an explanation of the reason for their repetition and the benefit of their re-mentioning.