Bible: Who Can Tell

Repeated words found across different books in the Bible (KJV):
2Sm 12:22
And he said, While the child was yet alive, I fasted and wept: for I said, Who can tell whether GOD will be gracious to me, that the child may live?

Eccl 6:12
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?

Eccl 8:7
For he knoweth not that which shall be: for who can tell him when it shall be?

Eccl 10:14
A fool also is full of words: a man cannot tell what shall be; and what shall be after him, who can tell him?

Jonah 3:9
Who can tell if God will turn and repent, and turn away from his fierce anger, that we perish not?