Sahih Bukhari Volume 009, Book 083, Hadith Number 042.
Narrated By Hisham's father : 'Umar asked the people, "Who heard the Prophet giving his verdict regarding abortions?" Al-Mughira said, "I heard him judging that a male or female slave should be given (as a Diya)." 'Umar said, "Present a witness to testify your statement." Muhammad bin Maslama said, "I testify that the Prophet gave such a judgment."