The Method of "expressing the cause" in Traditions about the Sale in Twelvers Jurisprudence

Inferring the criterion and the cause of religious laws along with inferringthe laws themselves are one of the tasks of jurisprudence and it's necessaryfor understanding the religious texts and laws. To achieve this, well knowing the cause (Ealla) and the reason (Hikma) of religious laws is necessary,but it is not easy. Overlooking this, is behind disagreement between juristsin different topics of jurisprudence. The sale is the most common and important contract and has occupied the major part of jurisprudential and legalissues. Thus, in comparison with other contracts, people ask more about it,which is obvious in hadith from Imams and expressing the cause in them. Inthis article, after explaining the terms, we mention the method of expressingthe cause in Arabic. Then we examine the method of "expressing the cause"in traditions about the Sale and the jurists opinion about it. The most common method is use of two letters, "PHA" and "LAM", and one kind of sentence called "Jomla Esmia". There is also disagreement between jurists as towhether those clauses in traditions are the cause or the reason, so we coulduse them in the same cases