The Messenger of Allah ﷺ said to a man, "You did such and such."The man replied, "No, by the One besides whom there is no god, I did not do it."Then Jibreel said to him, "He did indeed do it, but he has been forgiven for saying, 'There is no god but Allah.'"Hammad said, Thabit did not hear this directly from Ibn Umar. There was another man between them.
حدثنا عفان حدثنا حماد يعني ابن سلمة قال أخبرنا ثابت
أن رسول الله ﷺ قال لرجل فعلت كذا وكذا قال لا والذي لا إله إلا هو ما فعلت قال فقال له جبريل عليه السلام قد فعل ولكن قد غفر له بقول لا إله إلا الله قال حماد لم يسمع هذا من ابن عمر بينهما رجل يعني ثابتا
Its chain is daif due to disconnection, for Hammad bin Salama stated clearly that Thabit Banani did not hear it from Ibn Umar, but that there was a man between them whom he did not identify. This same chain will come again at 6102, and from Hasan at 5280, and from Abdul-Samad at 5986, both of them from Hammad bin Salama with this chain, in similar wording, but neither of them contains what Hammad said about Thabit not hearing it. Something similar has already passed from Ibn Abbas with sahih chains, the last of them at 2959, and it will also come again from his hadith during the Musnad of Ibn Umar at 5379. Something similar in meaning will also come from the hadith of Abu Hurairah at 8139, with one of the soundest of chains, in the manuscript of Hammam bin Munabbih.Qadi al-Malik Muhammad bin Sibghatullah Darami spoke at length about these hadiths in his Dhuyul al-Qawl al-Musaddad, pages 73–75, in response to Ibn Jawzi, since Ibn Jawzi had mentioned a hadith with this meaning from the hadith of Anas by way of Ibn Adi. What Darami said involves considerable strain, for the hadith of Anas is not in the Musnad, and the fact that its meaning appears in the Musnad through the narration of other companions does not serve as a valid response to Ibn Jawzi. The standard among the scholars of hadith, when judging whether a hadith is fabricated, daif, or sahih, is the chains through which it is narrated from the companion who is the source of that particular narration, even if it is sahih and firmly established through the narration of other companions. Imam Ahmad did not narrate this meaning in the Musnad from the hadith of Anas, as I have established through careful tracing.Then Sibghatullah Darami went to another strained length, quoting from Bayhaqi an interpretation of this meaning. Bayhaqi said, "If it is sahih, then what is meant by it is to clarify that a sin, however great, does not necessarily lead to the Fire, so long as one's belief is sound and one is among those for whom forgiveness has already been decreed in advance." He said, "This is not a specification for anyone after the Prophet ﷺ." Then Darami said, "It is possible that the man had been a disbeliever or a hypocrite, and then sincerely embraced monotheism, and this was accepted from him, so whatever sins came before it were erased." When the interpretation was not clear to Ibn Jawzi, he ruled it a fabrication. This is a strange strain, and I do not think it was unclear to Ibn Jawzi, nor is he the type of person who would readily accept such a hadith.Bayhaqi's interpretation is closer to being correct, but it is not precise, because the reasoning for the forgiveness is explicitly stated in the hadith itself, namely that the man sincerely declared "there is no god but Allah" with certainty, and so it applies generally to everyone who does the same. Allah's bounty is vast and His mercy is all-encompassing. However, we cannot make a definitive judgment about any specific case on this basis, because we cannot know sincerity, which is among the secrets of the heart, except to say what the hadith itself indicates, that whoever does that sincerely, testifying to the oneness of Allah, will be forgiven by Allah, as indicated by the explicit wording of the hadith in its narration.