"Prohibited to you (For marriage) are:- Your mothers, daughters, sisters; father's sisters, Mother's sisters; brother's daughters, sister's daughters; foster-mothers (Who gave you suck), foster-sisters; your wives' mothers; your step-daughters under your guardianship, born of your wives to whom ye have gone in,- no prohibition if ye have not gone in;- (Those who have been) wives of your sons proceeding from your loins; and two sisters in wedlock at one and the same time, except for what is past; for Allah is Oft-forgiving, Most Merciful;" - Quran 4:23 (read more)

"Narrated Abdullah ibn AbuDhubab: Iyas ibn Abdullah ibn AbuDhubab reported the Apostle of Allah (peace be upon him) as saying: Do not beat Allah's handmaidens, but when Umar came to the Apostle of Allah (peace be upon him) and said: Women have become emboldened towards their husbands, he (the Prophet) gave permission to beat them." - Sunan Abu Dawud 11:2141 (read more)

"If (all types of men) are taken, from the first, and one placed after another, like the Negro from Zanzibar, in the Southern-most countries, the Negro does not differ from an animal in anything except the fact that his hands have been lifted from the earth -in no other peculiarity or property - except for what God wished. Many have seen that the ape is more capable of being trained than the Negro, and more intelligent." - Nasīr al-Dīn al-Tūsī