Bukhari Collection: ::Book Number 3:: Hadith # 803
Narrated Abu Huraira:Allah's Apostle said, "The Prophet Abraham migrated with Sarah. The people (of the town where they migrated) gave her Ajar (i.e. Hajar). Sarah returned and said to Abraham, "Do you know that Allah has humiliated that pagan and he has given a slave-girl for my service?"