"And if you fear that you cannot act equitably towards orphans, then marry such women as seem good to you, two and three and four; but if you fear that you will not do justice (between them), then (marry) only one or what your right hands possess; this is more proper, that you may not deviate from the right course." - Quran 4:3 (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)

"Getting married at an early age is something that is confirmed by the book of Allah, the Sunnah of his Prophet (Sallallahu Alaihi wa Sallam), the consensus of the scholars and the actions of the companions, and the Muslims who came after them... There are many Ahadith which confirm that marriage at an early age was widespread among the companions and no one denied its permissibility. Getting married at an early age was not peculiar to the Prophet (Sallallahu Alaihi wa Sallam) as some people think, but it was general for him and for his Ummah." - Islamweb