Sahih Muslim
The Book Pertaining to the Merits of the Companions (Allah Be Pleased With Them) of the Holy Prophet (May Peace Be Upon Him) (Kitab Al-Fadail Al-Sahabah)
Book Number: 031 / Hadith Number: 5975
'A'isha reported that Allah's Apostle (may peace be upon him) did not marry any other woman till her (Khadija's) death.