Ecclesiastes 6:12 in the King James Version
For who knoweth what is good for man in this life, all the days of his vain life which he spendeth as a shadow? for who can tell a man what shall be after him under the sun?
Context
11 For there are many words that create vanity. What does that profit man?
12 For who knows what is good for man in life, all the days of his vain life which he spends like a shadow? For who can tell a man what will be after him under the sun?