Someone who had died was mentioned in an unfavorable way in the presence of the Prophet ﷺ, so he said, "Do not speak of your deceased except with good."
أخبرنا إبراهيم بن يعقوب قال حدثني أحمد بن إسحق قال حدثنا وهيب قال حدثنا منصور بن عبد الرحمن عن أمه
ذكر عند النبي ﷺ هالك بسوء فقال لا تذكروا هلكاكم إلا بخير
Its chain of transmission is sahih. Part of it has already appeared, h: 1828, and it is also in Kubra, h: 2062.