It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that a blind man had an umm walad (a slave woman who had borne him children) who used to revile the Prophet (peace and blessings be upon him) and speak ill of him (peace and blessings be upon him) a great deal. He would forbid her, but she would not desist; he would rebuke her, but she would not stop. One night, when she mentioned the Prophet (peace and blessings be upon him) (in an evil way), he could not bear it; he got up and brought a mighwal (a small dagger), placed it on her belly, then leaned upon it until he killed her. In the morning her two children were found between her legs, smeared with blood. This was mentioned to the Prophet (peace and blessings be upon him), so he (peace and blessings be upon him) stood up, gathered the people, then said: "I adjure by Allah the man over whom I have a right: whoever did this, let him stand up." Thereupon the blind man came forward, wailing, and said: "By Allah, O Prophet of Allah, I am her owner, and she is the mother of my children. I have two children from her who are like two pearls, and she was very gentle and kind to me. But she used to mention you and revile you. I would forbid her, but she would not stop; I would rebuke her, but she would not desist. Last night, when she mentioned you and said something offensive about you, I could not bear it. I got up for the mighwal, placed it on her belly, then leaned upon it until I killed her." The Prophet (peace and blessings be upon him) said: "I bear witness that her blood is unavenged."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11934