1047 – Ibn ʿAbbās (may Allah be pleased with them both) reported:

“A blind man had an umm walad (a concubine who had borne him a child) who used to curse the Prophet ﷺ and revile him. He would forbid her, but she would not stop. One night he took a mighwal—a staff tipped with a small, sharp blade—placed it on her abdomen, pressed down on her, and killed her. When the matter reached the Prophet ﷺ he said, ‘Bear witness that her blood is without liability.’” Reported by Abū Dāwūd, whose narrators are trustworthy. (1)

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Hadith grading
The ḥadith is ḥasan (sound). The author says: “Abū Dāwūd narrated it and its transmitters are reliable,” end quote. Both Abū Dāwūd and al-Mundhirī remained silent about it, and it was also recorded by al-Nasāʾī.
Al-Shawkānī said: “In this chapter there is also a report from Abū Barzah related by Abū Dāwūd and al-Nasāʾī.”
Ibn ʿAbd al-Hādī stated: “Imām Aḥmad used it as proof in the version transmitted by his son ʿAbd Allah.”

Lexical notes
• umm walad: The original form is “ummuhu” (his mother), so the plural may be “ummāt” when taken literally or “ummahāt” when taken from the root. An umm walad is a female slave who has borne her master a child with human features, even if miscarried or stillborn. The woman who cursed the Prophet was not a Muslim, which is why she dared commit this heinous act.
• mighwal: with a kasrah on the mīm and a silent, dotted ghayn; a stick fitted with a slender spear-point. Plural: maghawil.
• “He leaned upon her”: he pressed down on her with the stick until she died.
• “Her blood is without liability”: her blood was declared forfeit; no retaliation or blood-money is due.

Points derived from the three ḥadiths
1 – Linguistically, a murtadd (apostate) is “one who turns back.”