Ali said, "Whoever claims that we possess anything we recite besides the Book of Allah and this document," referring to a document hanging in the sheath of his sword, "has lied."In it was written, "The protection granted by the Muslims is one, extended even by the lowest among them. Whoever betrays a Muslim under that protection, upon him is the curse of Allah, the angels, and all people. No obligatory worship nor voluntary deed will be accepted from him on the Day of Resurrection."
من زعم أن عندنا شيئا نقرؤه إلا كتاب الله وهذه الصحيفة قال: -وصحيفة معلقة في قراب سيفه- فقد كذب. وفيها: وذمة المسلمين واحدة يسعى بها أدناهم. ومن أخفر مسلما فعليه لعنة الله والملائكة والناس أجمعين لا يقبل منه يوم القيامة صرف ولا عدل.
Bukhari narrated it in jizya (3172), and Muslim in Hajj (1370: 467, 468), both from the hadith of Amash, from Ibrahim Taymi, from his father, who said, "Ali gave us a sermon and said," then he mentioned it in a long hadith. The wording here is Muslim's.His saying, "the protection of the Muslims," means their guarantee of safety.His saying, "betrayed a Muslim," means he violated a Muslim's guarantee of safety by attacking a disbeliever who had been granted protection, and killed him.