Sahih Muslim | Book 8 | Hadith Number 3311

Narrated by 'Aisha (Allah be pleased with her)
'Aisha (Allah be pleased with her) reported that Allah's Apostle (may peace be upon him) married her when she was seven years old, and he was taken to his house as a bride when she was nine, and her dolls were with her; and when he (the Holy Prophet) died she was eighteen years old.