Sayyiduna Hudhaifah (may Allah be pleased with him) narrates: Two priests (or monks) from Najran, Aqib and Saeed, came to the service of the Prophet Muhammad (peace be upon him). They said: Send with us a trustworthy person who is truly trustworthy. So the Prophet Muhammad (peace be upon him) said: I will send with you a trustworthy person. The companions of the Prophet Muhammad (peace be upon him) became attentive to this. Then the Prophet Muhammad (peace be upon him) said: O Abu Ubaidah bin Jarrah, stand up. So the Prophet Muhammad (peace be upon him) sent him with those people.
Hadith Referenceصحیح ابن حبان / كتاب إخباره ﷺ عن مناقب الصحابة رجالهم ونسائهم بذكر أسمائهم رضوان الله عليهم أجمعين / 7000
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - المصدر نفسه: خ.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح على شرط مسلم