The words and letters of Ali, (peace be upon him), in relation to government and governance, are very significant in terms of understanding political jurisprudence; In this matter, her covenants with his agents and governors have a special place. In the section known as letters in Nahj al-Balaghah, there is a text called " From his covenant with Muhammad bin Abi-Bakr when he handed over Egypt to him", which is also very significant from the point of view of political literature; By examining this text, we come to the conclusion that this text is not actually his original contract and political order to Muhammad bin Abi-Bakr, and is a part of a comprehensive letter that Ali (peace be upon him) sent after the request of Muhammad bin Abi-Bakr about judgment and some other matters. In this article, using descriptive and analytical method and relying on library resources, the original testament of Ali (peace be upon him) to Muhammad bin Abi-Bakr has been introduced, and the comprehensive letter of Ali (peace be upon him)to Muhammad bin Abi-Bakr has also been introduced and comparisons have been made between the text of Nahj al-Balagha and some other texts of this comprehensive letter. By comparing these texts, we come to the conclusion that the text of Nahj al-Balagha is probably from one of the books of Abu Mikhnaf, who is a famous writer in Islamic history. The content of this comprehensive letter is very significant from several perspectives such as political jurisprudence, legal jurisprudence and ethics.