Hadith (Arabic: الحديث al-ḥadīth, pronounced: /ħadiːθ/; pl. aḥadīth; lit. "narrative") are narrations originating from the words and deeds of the Islamic prophet Muhammad. Hadith are regarded by traditional schools of jurisprudence as important tools for understanding the Quran and in matters of jurisprudence. Hadith were evaluated and gathered into large collections mostly during the reign of Umar bin Abdul Aziz during the 8th and 9th centuries. These works are referred to in matters of Islamic law and history to this day. The two main denominations of Islam, Shi`ism and Sunnism, have different sets of Hadith collections.