Ecclesiastes 8:17
"Then I beheld all the work of God, that a man cannot find out the work that is done under the sun: because though a man labour to seek it out, yet he shall not find it; yea farther; though a wise man think to know it, yet shall he not be able to find it."
Cross References (ranked by relevance)
He hath made every thing beautiful in his time: also he hath set the world in their heart, so that no man can find out the work that God maketh from the beginning to the end.
When I thought to know this, it was too painful for me;
O the depth of the riches both of the wisdom and knowledge of God! how unsearchable are his judgments, and his ways past finding out!
Which doeth great things and unsearchable; marvellous things without number:
Hast thou not known? hast thou not heard, that the everlasting God, the LORD, the Creator of the ends of the earth, fainteth not, neither is weary? there is no searching of his understanding.
Many, O LORD my God, are thy wonderful works which thou hast done, and thy thoughts which are to us-ward: they cannot be reckoned up in order unto thee: if I would declare and speak of them, they are more than can be numbered.
As thou knowest not what is the way of the spirit, nor how the bones do grow in the womb of her that is with child: even so thou knowest not the works of God who maketh all.
O LORD, how manifold are thy works! in wisdom hast thou made them all: the earth is full of thy riches.