The Messenger of Allah ﷺ said, "When your companion dies, leave him be and do not speak ill of him."
قال رسول الله ﷺ: إذا مات صاحبكم فدعوه، ولا تقعوا فيه.
Abu Dawud (4899) narrated it from Zuhayr bin Harb, who said, Waki narrated to us, Hisham bin Urwa narrated to us, from his father, from Ayesha, and he mentioned it. Its chain of transmission is sahih.