Hazrat Mufti Ebrahim Salejee (Daamat Barakaatuhu) mentioned:
Nabi (Sallallahu Alaihi Wasallam) had a constant smile on his face. If only we can practice on this mubaarak sunnah of Nabi (Sallallahu Alaihi Wasallam) and have a smile on our faces. In front of the wife we have our faces pulled up all the time as though we are telling them that I have all the fikr of the aakhirat. Nabi (Sallallahu Alaihi Wasallam) had that smile to teach us that we should not despair or cause others to despair. The doors of Allah’s mercy are always open, no matter who you are.