What are hadiths about calumny? Examples of hadiths about calumny…
According to Abu Hurayra (ra), the Prophet (saw) said, “Avoid the seven deadly sins.” The Companions (ra) asked, “O Messenger of Allah! What are they?” He said, “To associate partners with Allah; to practice sorcery; to kill someone, which Allah has forbidden except for a just cause (according to Islamic law); to practice usury, to consume the property of an orphan; to turn away on the day of battle, and to slander chaste believing women who would never even think of doing anything improper.” (al-Bukhari, al-Hudud, 44; Muslim, al-Iman, 145)
According to Abu Hurayra (ra), the Messenger of Allah (saw) said, “The gravest of the great sins is to go to great lengths in speaking unjustly against a Muslim’s honor…” (Abu Daʾud, al-Adab, 35)
According to Wathila b. al-Asqaʿ (ra), the Messenger of Allah (saw) said, “Verily, one of the worst lies is to claim falsely to be the son of someone other than one’s real father, or to claim to have had a dream one has not had, or to attribute to Messenger of Allah (saw) what he has not said.” (al-Bukhari, al-Manaqib, 5)
Abu Dharr (ra) heard the Prophet (saw) say, “If somebody accuses another of sinfulness (fusūq)) or accuses him of unbelief, such an accusation will revert to him (i.e.,, the accuser) if his Companion (the accused) is innocent.” (al-Bukhari, al-Adab, 44)
Source: Presidency Of Religious Affairs The Turkey, Islam Through Hadiths