Sahih al-Bukhari, Volume 4, Book 52, Hadith 275 (USC-MSA) ⓘ

Narrated Abu Burda: That his father said, "The Prophet sent Mu`adh and Abu Musa to Yemen telling them. 'Treat the people with ease and don't be hard on them; give them glad tidings and don't fill them with aversion; and love each other, and don't differ."

حَدَّثَنَا يَحْيَى، حَدَّثَنَا وَكِيعٌ، عَنْ شُعْبَةَ، عَنْ سَعِيدِ بْنِ أَبِي بُرْدَةَ، عَنْ أَبِيهِ، عَنْ جَدِّهِ، أَنَّ النَّبِيَّ صلى الله عليه وسلم بَعَثَ مُعَاذًا وَأَبَا مُوسَى إِلَى الْيَمَنِ قَالَ ‏ "‏ يَسِّرَا وَلاَ تُعَسِّرَا، وَبَشِّرَا وَلاَ تُنَفِّرَا، وَتَطَاوَعَا وَلاَ تَخْتَلِفَا ‏" ‏‏.‏