(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. (DE)
Reference (DE): Bulugh al-Maram 596 (DE)
In-book reference (DE): Book 3, Hadith 65 (DE)
English translation (DE): Book 3, Hadith 621 (DE)