"...If the party liable is mentally deficient, or weak, or unable Himself to dictate, Let his guardian dictate faithfully, and get two witnesses, out of your own men, and if there are not two men, then a man and two women, such as ye choose, for witnesses, so that if one of them errs, the other can remind her. The witnesses should not refuse when they are called on (For evidence)." - Quran 2:282 (read more)

"Narrated 'Abdullah bin 'Umar : The Jew brought to the Prophet a man and a woman from amongst them who have committed (adultery) illegal sexual intercourse. He ordered both of them to be stoned (to death), near the place of offering the funeral prayers beside the mosque." - Sahih Bukhari 7:62:64 (read more)

"Circumcision [of females] is not an inherited custom as some people claim, rather it is prescribed in Islam and the scholars are unanimously agreed that it is prescribed. Not a single Muslim scholar – as far as we know – has said that circumcision is not prescribed. Their evidence is to be found in the saheeh ahaadeeth of the Prophet (peace and blessings of Allaah be upon him), which prove that it is prescribed... Thus it is clear that the fuqaha’ of Islam are agreed that circumcision is prescribed for both males and females, and in fact the majority of them are of the view that it is obligatory for both. No one said that it is not prescribed or that it is makrooh or haraam." - Islam Q&A