and prohibition; yet there is a difference between permissibility or prohibition established by a revealed pronouncement and that established merely through the presumption of continuity. A contract or condition overrides what that presumption entails, but it does not override what the Lawgiver’s words establish. Reports from the Companions accord with this, as Umar, may Allah be pleased with him, said: “The stipulated conditions determine the limits of rights.”

As for rational reasoning, there are several considerations:

First: Contracts and conditions belong to the sphere of customary acts. The default regarding such acts is that they are not prohibited, and this presumption continues until evidence establishes their prohibition. Likewise, the default regarding tangible things is that they are not prohibited. Allah’s statement,

“He has already explained to you in detail what He has forbidden to you,”

applies generally to both tangible things and actions. If contracts and conditions are not prohibited, they are not invalid, for invalidity arises only from prohibition. If they are not invalid, they are valid.

Moreover, nothing in the Sharia indicates that contracts and conditions are prohibited as a class, except those whose lawfulness has been specifically established. Allah willing, we shall explain the meaning of the hadith of Ā’ishah and show that the absence of evidence of prohibition is itself evidence that something is not prohibited. Thus, the rational presumption of continuity and the absence of scriptural evidence establish that they are not prohibited. Entering into them is therefore either lawful or left unregulated, like tangible things that have not been prohibited.