(1)
A'ishah (RAA) narrated that the Messenger of Allah (ﷺ) said:
"Do not speak badly of the dead, they have already seen the result of (the deeds) that they sent on before them." Related by Al·Bukhari. (ID)
Reference (ID): Bulugh al-Maram 596 (ID)
In-book reference (ID): Book 3, Hadith 65 (ID)
English translation (ID): Book 3, Hadith 621 (ID)