Sahih Bukhari | Volume 9 | Hadith Number 420
Narrated by Al-Mughira bin Shu'ba
'Umar bin Al-Khattab asked (the people) about the Imlas of a woman, i.e., a woman who has an abortion because of having been beaten on her abdomen, saying, "Who among you has heard anything about it from the Prophet?" I said, "I did.'' He said, "What is that?" I said, "I heard the Prophet saying, "Its Diya (blood money) is either a male or a female slave.' " 'Umar said, "Do not leave till you present witness in support of your statement." So I went out, and found Muhammad bin Maslama. I brought him, and he bore witness with me that he had heard the Prophet saying, "Its Diya (blood money) is either a male slave or a female slave."