Qur'an (33:50) -
"O Prophet! surely We have made lawful to you your wives whom you have given their dowries, and those whom your right hand possesses out of those whom Allah has given to you as prisoners of war, and the daughters of your paternal uncles and the daughters of your paternal aunts, and the daughters of your maternal uncles and the daughters of your maternal aunts who fled with you; and a believing woman if she gave herself to the Prophet, if the Prophet desired to marry her-- specially for you, not for the (rest of) believers; We know what We have ordained for them concerning their wives and those whom their right hands possess in order that no blame may attach to you; " 
Qur'an (33:37) -
"But when Zaid had accomplished his want of her, We gave her to you as a wife, so that there should be no difficulty for the believers in respect of the wives of their adopted sons, when they have accomplished their want of them; and Allah's command shall be performed." 

Volume 7, Book 62, Number 21: Narrated Abu Huraira:
The Prophet said: Abraham did not tell lies except three. (One of them was) when Abraham passed by a tyrant and (his wife) Sara was accompanying him (Abu Huraira then mentioned the whole narration and said

(The tyrant) gave her Hajar. Sara said, "Allah saved me from the hands of the Kafir (i.e. infidel) and gave me Hajar to serve me." (Abu Huraira added

That (Hajar) is your mother, O Banu Ma'-As-Sama'

Sahih Bukhari Volume 7, Book 62, Number 18:
Narrated 'Ursa:
The Prophet asked Abu Bakr for 'Aisha's hand in marriage. Abu Bakr said "But I am your brother." The Prophet said, "You are my brother in Allah's religion and His Book, but she (Aisha) is lawful for me to marry."
wtf