Sahih Muslim 4525
صحيح مسلم#4525SahihIt has been narrated on the authority of Abu Masa that when the Messenger of Allah (ﷺ) deputed any of his Companions on a mission, he would say:Give tidings (to the people) ; do not create (in their minds) aversion (towards religion) ; show them leniency and do not be hard upon them
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 32:6