Here are 3 Bible verses about daydreaming from the Old and New Testaments of the Holy Bible (King James Version), sorted from most to least relevant.
Proverbs 28:19 KJV
He that tilleth his land shall have plenty of bread: but he that followeth after vain persons shall have poverty enough.
Ecclesiastes 5:7 KJV
For in the multitude of dreams and many words there are also divers vanities: but fear thou God.
Isaiah 56:10 KJV
His watchmen are blind: they are all ignorant, they are all dumb dogs, they cannot bark; sleeping, lying down, loving to slumber.