Sayyiduna Hudhayfah (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) sent a man as governor over Najran, and the people of Najran complained about him. He (peace and blessings be upon him) said: "I will send to you a trustworthy man who will fulfil the right of trust." The Companions of the Prophet (peace and blessings be upon him) looked on (eagerly), and he (peace and blessings be upon him) sent Sayyiduna Abu Ubaydah bin al-Jarrah (may Allah be pleased with him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النذور / 20149