(43) باب اسْتِحْبَابِ طَلاَقَةِ الْوَجْهِ عِنْدَ اللِّقَاءِ
Abu Dharr reported:
Allah's Apostle (ﷺ) said to me: Don't consider anything insignificant out of good things even if it is that you meet your brother with a cheerful countenance.
Reference: Sahih Muslim 2626
In-book reference: Book 45, Hadith 187
USC-MSA web (English) reference(deprecated numbering scheme): Book 32, Hadith 6359