Ecclesiastes 8:16
"When I applied mine heart to know wisdom, and to see the business that is done upon the earth: (for also there is that neither day nor night seeth sleep with his eyes:)"
Cross References (ranked by relevance)
And I gave my heart to seek and search out by wisdom concerning all things that are done under heaven: this sore travail hath God given to the sons of man to be exercised therewith.
It is vain for you to rise up early, to sit up late, to eat the bread of sorrows: for so he giveth his beloved sleep.
For all his days are sorrows, and his travail grief; yea, his heart taketh not rest in the night. This is also vanity.
The sleep of a labouring man is sweet, whether he eat little or much: but the abundance of the rich will not suffer him to sleep.
For he knoweth not that which shall be: for who can tell him when it shall be?
Thus I was; in the day the drought consumed me, and the frost by night; and my sleep departed from mine eyes.
There is one alone, and there is not a second; yea, he hath neither child nor brother: yet is there no end of all his labour; neither is his eye satisfied with riches; neither saith he, For whom do I labour, and bereave my soul of good? This is also vanity, yea, it is a sore travail.
All this have I seen, and applied my heart unto every work that is done under the sun: there is a time wherein one man ruleth over another to his own hurt.
I applied mine heart to know, and to search, and to seek out wisdom, and the reason of things, and to know the wickedness of folly, even of foolishness and madness: