صَحِيحُ مُسْلِمٍ
Sahih Muslim 1733 a
The Book of Jihad and Expeditions
The command to show leniency and avoid causing aversion (towards Islam)
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا وَكِيعٌ، عَنْ شُعْبَةَ، عَنْ سَعِيدِ بْنِ أَبِي بُرْدَةَ، عَنْ أَبِيهِ، عَنْ جَدِّهِ، أَنَّ النَّبِيَّ صلى الله عليه وسلم بَعَثَهُ وَمُعَاذًا إِلَى الْيَمَنِ فَقَالَ يَسِّرَا وَلاَ تُعَسِّرَا وَبَشِّرَا وَلاَ تُنَفِّرَا وَتَطَاوَعَا وَلاَ تَخْتَلِفَا .
It has also been narrated by Sa'd b. Abu Burda through his father through his grandfather that the Prophet (ﷺ) of Allah (ﷺ) sent him and Mu'adh (on a mission) to the Yemen, and said (by way of advising them): Show leniency (to the people) ; don't be hard upon them; give them glad tidings (of Divine favours in this world and the Hereafter) ; and do not create aversion. Work in collaboration and don't be divided.
Sahih Muslim, 1733 aSahihصحيح