Hudhaifa told that the people of Najran came to God's messenger and said, "Messenger of God, send us a trustworthy man." When he replied, "I shall certainly send you a trustworthy man who is genuinely trustworthy," the people[*] were looking to see if they would be appointed. He then sent Abu `Ubaida b. al-Jarrah.
*i.e., the Prophet's companions.
(Bukhari and Muslim.)