Rabi, the paternal aunt of Anas, broke the front tooth of a young girl. Her family sought pardon, but the girl's family refused. They then offered them compensation, but they still refused. So they came to the Prophet ﷺ, who ordered retaliation in kind.Anas bin Nadr said, "Messenger of Allah, will Rabi's tooth be broken? By the One who sent you with the truth, it shall not be broken."The Prophet ﷺ replied, "Anas, the Book of Allah prescribes retaliation."The people then accepted and pardoned her. So the Messenger of Allah ﷺ said, "Among the servants of Allah are some who, if they swear an oath by Allah, He fulfills it for them."
حدثنا محمد بن المثنى أبو موسى حدثنا خالد بن الحارث وابن أبي عدي عن حميد
كسرت الربيع عمة أنس ثنية جارية فطلبوا العفو فأبوا فعرضوا عليهم الأرش فأبوا فأتوا النبي ﷺ فأمر بالقصاص فقال أنس بن النضر يا رسول الله تكسر ثنية الربيع والذي بعثك بالحق لا تكسر فقال النبي ﷺ يا أنس كتاب الله القصاص قال فرضي القوم فعفوا فقال رسول الله ﷺ إن من عباد الله من لو أقسم على الله لأبرة
Bukhari narrated it in the Book of Reconciliation, chapter "Reconciliation in Cases of Blood Money" (Sulh, Bab al-Sulh fi al-Diyah), Hadith: 2703, 4499, 4500, 4611, 6894, through several routes from Humayd, with the same content, and in his version he explicitly stated hearing it directly. Thabit corroborated him, as found in Muslim, Hadith: 1675.