“A funeral passed by the
Prophet
(ﷺ) and they praised (the deceased) and spoke well of him
and
mentioned his good characteristics. He said: ‘(Paradise is)
guaranteed for him.’ Then another funeral passed by and they spoke
badly of him and mentioned his bad characteristics, and he the
Prophet (ﷺ) said: ‘(Hell is) guaranteed for him. You are the
witnesses of Allah on earth.’”
Sunan Ibn Majah Book 6, Hadith 60