"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)

"Due to the differences of both lives the Prophet (Sallallahu Alaihi wa Sallam) is not aware of what is going on in this world. He does not know who is asking help from him, and who is seeking child, wealth, wife, etc. ... On the other hand, if it is said that the Prophet (Sallallahu Alaihi wa Sallam) is alive in his grave, it does not mean that his life is similar to the life of those who are living in this world. So, if one seeks his help asks something from him he commits Shirk (polytheism)." - IslamWeb