"And the earth- We have spread it out, and set thereon mountains standing firm, and produced therein every kind of beautiful growth (in pairs)" - Quran 50:7 (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)

"The interpretation of the verse "And those of your women as have passed the age of monthly courses, for them the 'Iddah (prescribed period), if you have doubt (about their periods), is three months; and for those who have no courses (i.e. they are still immature) their 'Iddah (prescribed period) is three months likewise". He said: The same applies to the 'idaah for girls who do not menstruate because they are too young, if their husbands divorce them after consummating the marriage with them." - al-Tabari