The practices and traditions (Sunnah) of the Prophet which includes his sayings (Hadith) became the guide for Muslims in the understanding of the Quran and the practice of their religion. The Quran itself asserts that God has chosen in the Prophet an example for Muslims to follow. Besides this emulation of the Prophet in all aspects of life and thought, his sayings were assembled by various scholars. Finally they were codified in books of Hadith where the authentic were separated from the spurious. The Sunnah has always remained, after the Quran, the second source of everything Islamic.