The aim of this study is to properly investigate some of what is distinguished about the Islamic Sharia comparing to the earthly rules in terms of the reliability of its rules as well as the flexibility and accessibility to any time or place. The study a very important aspect of foundation science which is applying the Sharia rules on the issues that encounter people. This is because Allah issues rules and obligations to be applied on humans as a real and not make it an extreme image in the minds. Besides that the study aims to pinpoint the characteristic of Figh efforts with Ibadis scholars, and expose their methods in dealing with the updated realities and issues, and how much they depends on the tradition and interest in stating these rules. More importantly, the study shows that there is a relation between the fatwas of the mufti and the foundation and rules stated by the shara. The researcher studied the principle "the change of rulings do not mistaken by the change of time" a applicable and fundamental study. Although this principle is well-known with later Figh scholars, it has opened up fundamental and Fiqh dimensions that need to be examined staring from the statement of the principle and the consequences following that. Thus, this study comes to answer the following questions: To what extent we have to take this principle into guarantee based on the changing of the rules, and due to the change of times and traditions? What is the sharafundamental by which this principle is built? what is the clue behind applying these rules, and the nature of these rules that are changeable and the nature of this change? What is the impact of this principle in the application of Ibadi Figh when it comes to worshiping, financials , marriage, and sharapolitics. The most prominent results of this study are list below: The researcher believes that the statement of this principle should be changed as "The change of effort rulings do not mistaken by the sources" this is to avoid any problematic or ambiguity on this principle. The area of applying this principle is in the changing parts and not on the certainties. The principles has Figh applications with Ibadis in the earlier centuries, especially with books of Jawabat answers.