Ḥadīth , literally means "talk" or "discourse") in Islam refers to what Muslims believe to be a record of the words, actions, and the silent approval of the Islamic prophet Muhammad. Hadith have been called "the backbone" of Islamic civilization, and within that religion the authority of hadith as a source for religious law and moral guidance ranks second only to that of the Quran (which Muslims hold to be the word of God revealed to his messenger Muhammad). Scriptural authority for hadith comes from the Quran which enjoins Muslims to emulate Muhammad and obey his judgments (in verses such as 24:54, 33:21). While the number of verses pertaining to law in the Quran is relatively few, hadith give direction on everything from details of religious obligations (such as Ghusl or Wudu, ablutions for salat prayer), to the correct forms of salutations and the importance of benevolence to slaves. Thus the "great bulk" of the rules of Sharia (Islamic law) are derived from hadith, rather than the Quran.