'Unsearchable' in the Bible

Who doeth great things and unsearchable, Marvellous things without number:

Behold, God is great, and we know him not; The number of his years is unsearchable.

Great is Jehovah, and greatly to be praised; And his greatness is unsearchable.

As the heavens for height, and the earth for depth, So the heart of kings is unsearchable.