"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)

"....The women asked, "O Allah's Apostle! What is deficient in our intelligence and religion?" He said, "Is not the evidence of two women equal to the witness of one man?" They replied in the affirmative. He said, "This is the deficiency in her intelligence. Isn't it true that a woman can neither pray nor fast during her menses?" The women replied in the affirmative. He said, "This is the deficiency in her religion." - Sahih Bukhari 1:6:301 (read more)

"It is proven by the scholars who studied the Prophet’s biography in detail that he ate mutton that had been poisoned by a Jewish woman in Khaybar, ... When his final illness came, he (peace and blessings of Allaah be upon him) said: “O ‘Aa’ishah, I still feel the pain of the food that I ate in Khaybar, and this time I feel that my aorta is being cut from that poison.” Narrated by al-Bukhaari in his Saheeh. So there is no room for doubt that this poison affected his body, since it is proven in al-Saheeh and elsewhere." - Islam Q&A