Sahih Bukhari | Volume 3 | Hadith Number 465

Narrated by 'Aisha
(The wife of the Prophet) Allah's Apostle and Abu Bakr hired a man from the tribe of Bani-Ad-Dil as an expert guide who was a pagan (follower of the religion of the pagans of Quraish). The Prophet and Abu Bakr gave him their two riding camels and took a promise from him to bring their riding camels in the morning of the third day to the Cave

of Thaur.