Adhere to the Book of Allah, because it is the strong rope, clear light, benefitting cure, quenching for thirst, protection for the adherent and deliverance for the attached. It does not curve so as to need straightening and does not deflect so as to be corrected. Frequency of its repetition and its falling on the ears does not make it old. Keep Allah in mind regarding the Quran. No one should excel you in acting upon it. (Nahjul Balagha, Letter no. 47, and Sermon no. 156).