Arabic text
عن أبي ذر رضي الله عنه قال: قال لي النبي صلى الله عليه وسلم: «لَا تَحْقِرَنَّ مِنَ الْمَعْرُوفِ شَيْئًا، وَلَوْ أَنْ تَلْقَى أَخَاكَ بِوَجْهٍ طَلْقٍ».
Translation
Abu Dharr (may Allah be pleased with him) reported: The Prophet (may Allah's peace and blessings be upon him) said to me: "Do not belittle any good deed, even if it be meeting your brother with a cheerful face."
Explanation
The Prophet (may Allah's peace and blessings be upon him) urges us to do good and not belittle any act of goodness, even if it is simple. An example is meeting one another with a cheerful face. A Muslim should be keen on doing this, for it brings a sense of friendliness and joy to his Muslim brother.
Source: HadeethEnc.com