Authenticity of Jurisprudential Hadiths Common among Sunnite and Shiite

As one of the ways to reach Sunnah^* common hadith is the subject of this research. Common hadith is a text made of same or similar words that is achieved from two different way of transition, Shiite and Sunniteوof similarsmition.me ch is hs . This type of hadith forms a notable volume in Jurisprudential hadiths. This composition tries to declare the true relation between hadith and Sunnah. Common hadith has a special position in reaching Sunnah. We would like to know how much authenticity this joint makes in our way achieving Sunnah. We investigate authenticity of common hadith via comparing it with successive hadith. We also use theory of probability to proof authenticity of common hadith. In the above-mentioned comparison we verify negation in probability of collusion on untruth in common hadith just like succession. If we negate the probability of collusion regarding dissension between Shiite and Sunnite then we become able to proof the authenticity of common hadith just as succession. Existence of a common accepted point among Shiite and Sunnite, as the reason of joint in texts, is the main provision in this argument. Holy prophet Mohammad ^PBUH plays the role of this joining point. In theory of probability we tried to form a random statistical sample, by making suitable statistical population and studying variables, that supplies all variables. Examples of common hadiths attained from this sample are authenticated by famous authentication criterions. Finally, we calculate authenticity of the forenamed joint, using formula of conditional probability.