كتاب المقدمات
1
The Book of Miscellany
Anas (May Allah be pleased with him) reported:
The Prophet (ﷺ) said, "Make things easy and do not make them difficult, cheer the people up by conveying glad tidings to them and do not repulse (them)."

[Al-Bukhari and Muslim].

وعن أنس رضي الله عنه عن النبى صلى الله عليه وسلم قال‏:‏ “يسروا ولا تعسروا وبشروا ولا تنفروا ‏(‏‏(‏متفق عليه‏)‏‏)‏‏.‏
Arabic/English book reference : Book 1, Hadith 637