There is no doubt that the subject of Imam Mahdi is a topic agreed upon by Muslims, and many religions and the promised Mahdi is the son of the Prophet Mohammad. A few days before the death of the fourth ambassador, Ali bin Mohammad al-Samri, Imam Mahdi sent a message to his ambassador saying: “In the name of God, the Most Merciful, the Most Merciful, O Ali bin Mohammad al-Samari, the greatest of God; And between six days, gather your command and do not recommend anyone to take your place after your death, for complete occultation has occurred, and there is no reappearance except after the permission of Allah, the Exalted, mentioning him, and that is after a long period, hardness of hearts, and the earth being filled with oppression”. Accordingly, in this article, which has been done with a historical approach and review of documents and narrative sources. We try to use the sources with high accuracy, we will address the subject of the philosophy of the great Occultation of Imam Mahdi and we will talk in it about the philosophy of occultation and its benefits in brief, relying on the book “Imam Mahdi and the Promised Day of Khalil Rzq”.