The Messenger of God said, "Whosoever commits to memory for my ummah (religious community) forty traditions concerning religion will be resurrected by God in the company of the jurists and the learned." The learned scholars of Islam have composed books of forty traditions on a wide range of themes, such as jihad (struggle), comportment (adab), or the sacred sayings (hadith qudsi, or words of the Prophet which quote God speaking, but are not part of the Quran and are not wahy or revelation).

In a humble effort to be faithful to this tradition of collecting and publishing forty traditions of the Prophet, this book takes as its theme the subject of divine mercy, which comes from God and manifests in His Prophet and His religion.