Sahih al-Bukhari 7317, 7318
Holding Fast to the Qur'an and Sunnah
Exerting oneself to find out the proper legal verdict which is in harmony with what Allah has revealed
Narrated 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 (ﷺ) 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 (ﷺ) saying, "Its Diya (blood money) is either a male slave or a female slave."