"Such of your women as have passed the age of monthly courses, for them the prescribed period, if ye have any doubts, is three months, and for those who have no courses (it is the same): for those who carry (life within their wombs), their period is until they deliver their burdens: and for those who fear Allah, He will make their path easy." - Quran 65:4 (read more)

"O Allah's Apostle! We asked you for mounts, but you took an oath that you would not give us any mounts; we think that you have forgotten your oath.' He said, 'It is Allah Who has given you mounts. By Allah, and Allah willing, if I take an oath and later find something else better than that. then I do what is better and expiate my oath.'" - Sahih Bukhari 7:67:427 (read more)

"With regard to the criticism of [female] circumcision by some doctors, and their claim that it is harmful both physically and psychologically. This criticism of theirs is not valid. It is sufficient for us Muslims that something be proven to be from the Prophet (peace and blessings of Allaah be upon him), then we will follow it,... If it were harmful, Allaah and His Messenger (peace and blessings of Allaah be upon him) would not have prescribed it for us." - Islam Q&A