Jami` at-Tirmidhi 3796
جامع الترمذي#3796SahihNarrated Hudhaifah bin Al-Yaman:that Al-'Aqib and As-Sayyid (two of the leaders of the Christians of Najran) came to the Prophet (ﷺ) and said: "Send with us your trustworthy one." He said: "I shall send with you a trustworthy one who is truly a trustworthy one." So the people desired that, and he sent Abu 'Ubaidah, may Allah be pleased with him
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirSahih
Al-AlbaniSahih
Bashar Awad MaaroufHasan Sahih
Zubair Ali ZaiSahih - Agreed Upon
In-book reference: 49:195