'Abdallah b. ‘Amr reported the Prophet as saying, “The passing away of the world would mean less to God than the murder of a Muslim man.”
Tirmidhi and Nasa’i transmitted it. Some traced it only to the Companion, and that is the soundest view. Ibn Majah transmitted it on the authority of al-Bara’ b. 'Azib.
Abu Juhaifa said he asked ‘Ali whether he had any instruction not contained in the Qur’an and he replied, “By Him who split the seed and created the soul, I have nothing but what is in the Qur’an, except understanding which a man is given regarding His Book and what is in the document.” He asked him what the document contained, and he replied, “Blood wit, the setting free of a prisoner, and that a Muslim should not be killed for an infidel.”
Abu Sa'id and Abu Huraira reported God's Messenger as saying, “If the inhabitants of heaven and earth were to share in the blood of a believer, God would overturn them in hell.”
Tirmidhi transmitted it, saying this is a gharib tradition.
He said that ar-Rubaiyi‘, paternal aunt of Anas b. Malik, broke the front tooth of a girl of the Ansar, and when they went to the Prophet he ordered retaliation to be taken. Then Anas b. an-Nadr, paternal uncle of Anas b. Malik, said, “No, by God, her front tooth will not be broken, Messenger of God." He replied, “Anas, God’s decree is retaliation." But the people were agreeable to accepting a fine, so God’s Messenger said, “Among God’s servants there are those who, if one adjured God, would consent to it."
