There are some of Allah’s servants who, if they take an oath by Allah, Allah fullfils them.
Imam Ahmad recorded that Anas bin Malik (رضي الله عنه) said, “Ar-Rabi` (رضي الله عنها) (his aunt) broke the tooth of a girl, and the relatives of Ar-Rabi` requested the girl’s relatives to forgive (the offender), but they refused. So, they went to the Prophet who ordered them to bring about retaliation. Anas bin An-Nadr (رضي الله عنه), her brother, asked, `O Allah’s Messenger (صلى الله عليه وسلم )! Will the tooth of Ar-Rabi` be broken’ The Messenger of Allah said, `O Anas! The Book of Allah prescribes retaliation.’ Anas said, `No, by Him Who has sent you with the Truth, her tooth will not be broken. ‘ Later the relatives of the girl agreed to forgive Ar-Rabi` and forfeit their right to retaliation. The Messenger of Allah said,
«إن من عباد الله من لو أقسم على الله لأبره»
(There are some of Allah’s servants who, if they take an oath by Allah, Allah fullfils them.)” It was recorded in the Two Sahihs.