"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)

"And he [Muhammad] had their hands and feet cut off. Then he ordered for nails which were heated and passed over their eyes, and whey were left in the Harra (i.e. rocky land in Medina). They asked for water, and nobody provided them with water till they died (Abu Qilaba, a sub-narrator said, 'They committed murder and theft and fought against Allah and His Apostle, and spread evil in the land.')" - Sahih Bukhari 1:3:63 (read more)

"Offering condolences to a kaafir if one of his loved ones – a friend or relative – dies... Some of the scholars say that it is haraam to offer condolences to them, and some say that it is permissible. Some of them added further details and said that if that serves an interest, such as the hope that they may become Muslim and it may ward off their evil which could not be done except by offering condolences, then it is permissible, otherwise it is haraam." - Muhammad Saed Abdul-Rahman