Allah's Messenger (ﷺ) was neither a Fahish (one who had a bad tongue) nor a Sabbaba (one who abuses others) and he used to say while admonishing somebody, "What is wrong with him? May dust be on his forehead!"
Sahih al-Bukhari Book 78, Hadith 76
← Previous Hadith That he heard the Prophet (ﷺ) saying, "If somebody accuses another of Fusuq (by calling him 'Fasiq' i.e. a wicked person) or accuses him of Kufr, such an accusation will revert to him (i.e. the accuser) if his companion (the accused) is innocent."

Sahih al-Bukhari Book 78, Hadith 75 Next Hadith → (who was one of the companions who gave the pledge of allegiance to the Prophet (ﷺ) underneath the tree (Al-Hudaibiya)) Allah's Messenger (ﷺ) said, "Whoever swears by a religion other than Islam (i.e. if somebody swears by saying that he is a non-Muslim e.g., a Jew or a Christian, etc.) in case he is telling a lie, he is really so if his oath is false, and a person is not bound to fulfill a vow about a thing which he does not possess. And if somebody commits suicide with anything in this world, he will be tortured with that very thing on the Day of Resurrection; And if somebody curses a believer, then his sin will be as if he murdered him; And whoever accuses a believer of Kufr (disbelief), then it is as if he killed him."

Sahih al-Bukhari Book 78, Hadith 77