Undetermined Ṣidāq in the Mirror of Jaʿfarī Jurisprudence and Iranian Legal Code

Floating dowry is a type of dowry that is not specified in the text of the contract, but its calculation mechanism is specified. In this case, the parties open the dowry to be appointed according to the custom of the day or the opinion of one of the parties or a third arbitrator. Now the question comes to mind whether a marriage whose dowry is indefinite and floats in time is valid or not? Accordingly, the authors, while analyzing various views, have studied the above-mentioned discussion from the perspective of Imami jurisprudence and Iranian law and have studied it scientifically. The method of this paper is to analyze-description. The research data was collected by using the library. Research findings it shows that concise knowledge is sufficient to remove the ambiguity of the dowry and there is no need for detailed knowledge. Therefore, it is not necessary for the dowry to be specific at the time of marriage, but it is enough to be able to determine it in the future.