“A man brought the killer of his relative to the Messenger of Allah (ﷺ) and the Messenger of Allah (ﷺ) said: 'Pardon him,' but the refused. He said: 'Take the blood money,' but he refused. He said: 'Go and kill him, but then you will be like him.’ Someone caught up with him and reminded him that the Messenger of Allah (ﷺ) had said: 'Go and kill him, but then you will be like him.’ So he let him go. He said: So he was seen dragging his strap going to his family. He said: It seemed that he had tied him up.

It's narrated that AbdurRahman bin AlQasim said "Then it is not (permissible) for anyone after the Prophet ﷺ to say 'Go and kill him, but then you will be like him.' "
Sunan Ibn Majah Book 21, Hadith 77
← Previous Hadith “A man killed (another) during the time of the Messenger of Allah (ﷺ) and was referred to the Prophet (ﷺ). He handed him over to the victim's next of kin, but the killer said: 'O Messenger of Allah (ﷺ), by Allah I did not mean to kill him.' The Messenger of Allah (ﷺ) said to the next of kin, 'If he is telling the truth and you kill him, you will go to Hell.' So he let him go. He had been tied with a rope, and he went out dragging his rope, so he became known as Dhan-Nis'ah (the one with the rope).

Sunan Ibn Majah Book 21, Hadith 76 Next Hadith → “I only know it from Anas bin Malik who said: 'No case involving retaliation was referred to the Messenger of Allah (ﷺ) but he enjoined forgiveness.”

Sunan Ibn Majah Book 21, Hadith 78