Abu Dharr (May Allah be pleased with him) reported: The Prophet (PBUH) said, "Do not belittle any good deed, even meeting your brother (Muslim) with a cheerful face".
[Muslim].

Commentary: We learn from this Hadith that meeting somebody cheerfully is also a virtue for two reasons. Firstly, it is a sign of good manners. Secondly, it creates affection and friendship among the Muslims which is a meritorious act.