Hadith Al Thaqalayn AStudy of Its Tawatur

Imam Khumayni began his wasiyyah or will with the mention of this tradition of the Prophet (S), known as Hadith al­ Thaqalayn. In the prologue to his wasiyyah he pointed out that whatever tragedies and disasters befell the Muslim world during the last fourteen centuries have been mainly due to its estrangement from the Thaqalayn, the twofold legacy of the Prophet (S) in the form of the Qur'an and the Ahl al­Bayt (A).
The Meaning of Tawatur: As we know, the tradition or ahadith of the Holy Prophet (S) recorded in the books of Muslim traditionists begin with chains of transmitters on whose authority the traditionalist reports the Prophet's acts or statements. Experts of hadith amongst Muslims have developed certain criteria for assessing the reliability of different chains of transmission and ascertaining the authenticity of the contents of traditions. They have developed a terminology with terms denoting various classifications of hadith depending on the character, strength or weakness of narrators and other factors, such as mutawatir, ahad, sahih, hasan, qawi, da`if, etc.

By tawatur is meant the multiplicity of the sources of a certain report that leads to certitude in the listener that the report is indeed true. One's knowledge of the existence of distant countries and towns and such historical figures as Cyrus or Napolean may be said to be based on the tawatur of reports that one hears about them. So also is one's knowledge of the contemporary events not witnessed by him.