The behavior and actions of the innocents are one of the guiding sources of jurisprudence in solving new problems and common problems. In this regard, one of the important rules in jurisprudence, especially specialized jurisprudence, is the rule of following the Prophet and the Imam. Contrary to the widespread use of the rule in jurisprudence, coherent arguments about its meaning, scope, and effectiveness have not been conducted.There is a great difference between jurists in what tasi is and in which of the Prophet's actions it was obligatory and in which it was not obligatory.This research has followed the investigation of the existing sayings and the provisions of the mentioned rule with regard to some anecdotal evidence.As a result, in the nature of Tasi, neither doing the verb with the intention of its true form is a condition in all cases, nor that it is not a condition in any case. If the knowledge is of the aspect of the verb, the opposite cannot be intended, and in cases where the aspect of the verb is unclear, the aspect of the verb is not valid.The evidence of narrations such as the verse of the Prophet being an example due to his appearance in guidance according to the well-known basis, the analogy of the word "lakum" in the absence of obligation and the presence of general knowledge to the absence of obligation of complete compliance with the behavior of the Prophet, the appearance in absolute obedience and the example is not obligatory