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: 5947
Anas reported Allah's Messenger (may peace be upon him) as saying: For every Umma there is a man of trust and the man of trust of this Umma is Abu 'Ubaida b. Jarrah.