The book al-Kafi fi Ilm al-Din ("What is Sufficient in the Knowledge of the Faith") is a Twelver Shiah hadith collection compiled by Muhammad Yaqub Kulayni.It is divided into three Usul al-Kafi, which is concerned with the principle of religion, Furu al-Kafi, which is concerned with the details of religious law, and Rawdat (or Rauda) al-Kafi, which is concerned with various religious aspects and includes some writings of the Imams. In total, al-Kafi comprises 16,199 narrations; however, as with all Shiah hadith books, every single hadith must be individually examined through the science of hadith. .