Sahih Muslim 1682 a
The Book of Oaths, Muharibin, Qasas (Retaliation), and Diyat (Blood Money)
The Diyah for a fetus; and the Diyah for accidental killing and the ambiguous killing must be paid by the shahiqilah of the killer
Al-Mughira b. Shu'ba reported that a woman struck her co-wife with a tent-pole and she was pregnant and she killed her. One of them belonged to the tribe of Lihyan. Allah's Messenger (ﷺ) made the relatives of the murderer responsible for the payment of blood-wit on her behalf, and fixed a slave or a female slave as the indemnity for what was in her womb. One of the persons amongst the relatives of the murderer said: Should we pay indemnity for one who, neither ate, nor drank, nor made any noise, who was just like a nonentity? Thereupon Allah's Messenger (ﷺ) remarked: He speaks rhymed phrases like the people of the desert. He did impose indemnity upon them.