Musnad Abu Ya'la al-Mawsili 117:207

Ahmad ibn Umar al-Waki'i narrated to us, Mu'ammal ibn Isma'il narrated to us, Hammad ibn Salamah narrated to us, from Thabit, from Anas, who said: The Messenger of Allah (ﷺ) said: "There is no Muslim who dies, and four people from the households of his nearest neighbors testify for him that they do not know anything about him except good, except that Allah says: 'I have accepted your knowledge, and I have forgiven him for what you do not know.'"