Proverbs 17:22 - A merry heart doeth good like a medicine
Ecclesiastes 10:19 - A feast is made for laughter.
Psalms 126:1 - 3
1 When the LORD turned again the captivity of Zion, we were like them that dream.
2 Then was our mouth filled with laughter, and our tongue with singing: then said they among the heathen, The LORD hath done great things for them.
3 The LORD hath done great things for us; whereof we are glad.