Send with us a person who should teach us Sunnah and al-Islam, whereupon he (the Holy Prophet) caught hold of the hand of Ubaida and said: He is a man of trust of this Umma. (Using translation from Muslim 2419b)
أَنَّ أَهْلَ الْيَمَنِ قَدِمُوا عَلَى رَسُولِ اللهِ ﷺ فَقَالُوا ابْعَثْ مَعَنَا رَجُلًا يُعَلِّمُنَا السُّنَّةَ وَالْإِسْلَامَ فَأَخَذَ بِيَدِ أَبِي عُبَيْدَةَ ؓ فَقَالَ هَذَا أَمِينُ هَذِهِ الْأُمَّةِ