Authentic chain
Sunan an-Nasa'i 4739
he heard Tawus narrate from Ibn 'Abbas, from 'Umar, may Allah be pleased with him, that he asked about the ruling of the Messenger of Allah concerning that. Hamal bin Malik stood up and said: "I was married to two women, and one of them struck the other with a tent pole and killed her and her…
فَقَضَى النَّبِيُّ صلى الله عليه وسلم فِي جَنِينِهَا بِغُرَّةٍ وَأَنْ تُقْتَلَ بِهَا .