"...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)

"Our people [the Muslims] observing thus the occupations of the Jews and the Christians concluded that the religion of the Jews must compare unfavorably as do their professions, and that their unbelief must be the foulest of all, since they are the filthiest of all nations. Why the Christians, ugly as they are, are physically less repulsive than the Jews." - al-Jahiz