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 fetus. The Prophet ruled that a slave be given (as Diyah) for her fetus and that she be killed (for killing the other woman)." (Using translation from Nasāʾī 4739)  

أَنَّهُ نَشَدَ قَضَاءَ النَّبِيِّ ﷺ فِي ذَلِكَ فَقَامَ حَمَلُ بْنُ مَالِكٍ فَقَالَ «كُنْتُ بَيْنَ حُجْرَتَيِ امْرَأَتَيَّ فَضَرَبَتْ إِحْدَاهُمَا الْأُخْرَى بِمِسْطَحٍ فَقَتَلَتْهَا وَجَنِينَهَا فَقَضَى النَّبِيُّ ﷺ فِي جَنِينِهَا بِغُرَّةٍ وَأَنْ تُقْتَلَ بِهَا»