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). 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.