Hadith of the Quran and Sunnah accept the authenticity of the related Hadith of the two weighty things ("Hadith al-Thaqalayn"). In this hadith, Muhammad referred to the Qur'an and "Ahl al-Bayt" ('people of the house', Muhammed's family) as the two weighty things. Although the hadith is accepted by both Sunnis and Shi'as, the two groups differ on the exact wording of what Muhammad said, as well as how to interpret these words. The Shi'as use the Hadith of the two weighty things to prove their claim that Muhammad meant for all his successors to be from his own family ("Ahl al-Bayt"). The Sunnis reject this view
Criticism of Hadith "in the early Islamic centuries there could be no better way of promoting a cause, an opinion, or a faction than to cite an appropriate action or utterance of the Prophet." This gave strong incentive to fabricate hadith. According to Daniel Brown, the major causes of corruption of Hadith literature are: Other criticism made of ahadith include Orthodox Muslims do not deny the existence of false "hadith", but believe that through the work of hadith scholars, these false "hadith" have been largely eliminated. al-Shafi'i himself, the founder of the proposition that “sunna” should be made up exclusively of specific precedents