The Messenger of Allah ﷺ said, "When your companion dies, leave him be and do not speak ill of him."
حدثنا زهير بن حرب حدثنا وكيع حدثنا هشام بن عروة عن أبيه
قال رسول الله ﷺ إذا مات صاحبكم فدعوه ولا تقعوا فيه
[Its isnad is sahih] Tirmidhi collected it in the Chapter on Merits, section on the virtue of the wives of the Prophet ﷺ, no. 3895, from the hadith of Hisham, with this wording, and he said, hasan gharib sahih. Ibn Hibban also graded it sahih, no. 1983.