SAHIH BUKHARI

Volume 1, Book 3, Number 88:

Narrated 'Abdullah bin Abi Mulaika:

'Uqba bin Al-Harith said that he had married the daughter of Abi Ihab bin 'Aziz. Later on a wo- man came to him and said, "I have suckled (nursed) Uqba and the woman whom he married (his wife) at my breast." 'Uqba said to her, "Neither I knew that you have suckled (nursed) me nor did you tell me." Then he rode over to see Allah's Apostle at Medina, and asked him about it. Allah's Apostle said, "How can you keep her as a wife when it has been said (that she is your foster-sister)?" Then Uqba divorced her, and she married another man.