It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with him) that Sayyiduna Umar asked the people for a precedent from the decisions of the Prophet (peace and blessings be upon him) regarding an issue. Then Sayyiduna Haml bin Malik bin Nabighah came and said: Once I was in the houses of my wives when one of them struck another with a tent pole, causing her death, and the child in her womb also died. The Prophet (peace and blessings be upon him) ruled that for the child in her womb, a slave man or woman should be given, and that the killer should be killed in retaliation for the murdered woman.
Hadith Referenceمسند احمد / مسند المدنيين رضي الله عنهم اجمعين / 16729
Hadith Gradingحکم دارالسلام:إسناده صحيح، وقوله: أن تقتل لفظة شاذة ، والمحفوظ: «أنه قضى بديتها على عاقلة القاتلة»