Musnad Abu Ya'la al-Mawsili 113:25

Abu Khaythama and Abu Bakr ibn Abi Shaybah narrated to us, they said: Isma'il ibn Ibrahim narrated to us, from Hajjaj ibn Abi 'Uthman, Abu Raja' the freed slave of Abu Qilabah narrated to me, from Abu Qilabah, he said: Anas said: The Messenger of Allah (may Allah bless him and grant him peace) said: "For every nation there is a trustworthy one, and our trustworthy one, O this nation, is Abu 'Ubaydah ibn al-Jarrah."