What does the bible say about smiling?

Yes although it may depend on the translation that you use. I have the New Living Translation which makes things a little easier to read and understand. In my version it can be found in Numbers 6:25 May the Lord smile on you and be gracious to you., Psalm4:6 Many people say, "Who will show us better times? Let your face smile on us, Lord., and Psalm 67:1. May God be merciful and bless us, May His face smile with favor on us.There may be other places and other translations that have the Word smile.