Sahih Muslim Book 16, Hadith Number 4174.

Chapter : Blood-wit of the child in the womb; and the essentiality of blood-with in case of unintentional murder and in case of the quasi-intentional murder.

Miswar b. Makhrama reported that ‘Umar b. Khattab consulted people about the diyat of abortion of an unborn child. Mughira b. Shu’ba said: I bear witness to the fact that Allah’s Messenger (may peace be upon him) gave judgment about it that a good quality of slave or female slave should be given for it. Thereupon ‘Umar said: Bring one who may bear witness to you. Then Muhammad b. Maslama bore witness to him.