"...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 Qatada: Anas bin Malik said, "The Prophet used to visit all his wives in a round, during the day and night and they were eleven in number." I asked Anas, "Had the Prophet the strength for it?" Anas replied, "We used to say that the Prophet was given the strength of thirty (men)." And Sa'id said on the authority of Qatada that Anas had told him about nine wives only (not eleven)." - Sahih Bukhari 1:5:268 (read more)

"We must know that [wife] beating is a punishment in Islamic religious law,....No one should deny this because this was permitted by the Creator of Man, and because when you purchase an electric appliance or a car you get instructions – a catalogue, explaining how to use it. The Creator of Man has sent down this book [the Quran] in order to show man which ways he must choose....We shouldn't be ashamed before the nations of the world who are still in their days of ignorance, to admit that these [beatings] are part of our religious law..." - Muslim cleric on Qatar TV