It was recorded by al-Bukhārī (7/176–178), Muslim, and Aḥmad (5/321).
The third route is from Abū al-Ashʿath al-Ṣanʿānī, from him. He said: “The Messenger of Allah, peace and blessings be upon him, took a pledge from us as he took it from the women: that we would not associate anything with Allah, nor steal, nor commit adultery, nor kill our children, nor should any of us level slander at another, [nor disobey him in what is right]. Whoever among you fulfils [this]...” The hadith. It was recorded by Muslim and Aḥmad (5/320); Ibn Mājah (2/129) recorded its final portion.
As the scholars have said, the hadith refutes the Khārijites, who declare people unbelievers on account of sins, as well as the Muʿtazilites, who hold that a sinful person who dies without repentance must be punished. For the Prophet, peace and blessings be upon him, stated that he is subject to Allah’s will; he did not say that Allah must punish him.
I say: The same applies to His saying, Most High: “Indeed, Allah does not forgive associationism with Him, but He forgives what is less than that for whomever He wills.” Thus, the Exalted distinguished between associationism and other sins: He informed us that He does not forgive associationism, whereas all else is subject to His will—if He wills, He punishes its perpetrator, and if He wills, He forgives him. The verse and the hadith must necessarily be understood as referring to one who has not repented. Otherwise, one who repents from associationism is forgiven; then repentance from anything less than it is even more deserving of forgiveness. The verse has distinguished between the two.
This is the proof I used against an upstart faction that has emerged in the present age. At times, they declare Muslims unbelievers because of major sins; at other times, they categorically assert that such sins are not subject to Allah’s will and are forgiven only through repentance. Thus, they equated them with associationism and thereby contradicted the Quran and the sunnah. When I established this proof against them over many hours—indeed, at numerous sittings—some of them returned to what is correct and became among the finest of the Salafi youth. May Allah guide the rest.
His statement, “nor should he level slander,” means that he should not accuse another with al-ʿaḍīhah (a false and slanderous accusation), which is calumny and lies.