CHEERFUL FACE H 905 "Do not look down upon doing the least amount of good, even greeting your brother with a cheerful face (is a good deed)." R 905 Muslim with a chain up to Abu Dharr who related that the Prophet, praise and peace be upon him, said this.
892- وعن أَبي ذَرٍّ رضي الله عنه ، قَالَ : قَالَ لي رسول الله صلى الله عليه وآله وسلم : "لا تَحقِرَنَّ منَ الْمَعرُوف شَيْئاً ، وَلَوْ أنْ تَلْقَى أخَاكَ بِوَجْهٍ طَلْقٍ" رواه مسلم .