Job 28:21
"Seeing it is hid from the eyes of all living, and kept close from the fowls of the air."
Cross References (ranked by relevance)
At that time Jesus answered and said, I thank thee, O Father, Lord of heaven and earth, because thou hast hid these things from the wise and prudent, and hast revealed them unto babes.
In whom are hid all the treasures of wisdom and knowledge.
That it might be fulfilled which was spoken by the prophet, saying, I will open my mouth in parables; I will utter things which have been kept secret from the foundation of the world.
For verily I say unto you, That many prophets and righteous men have desired to see those things which ye see, and have not seen them; and to hear those things which ye hear, and have not heard them.