Proverbs 25:3 in the World English Bible
As the heavens for height, and the earth for depth, so the hearts of kings are unsearchable.
Context
2 It is the glory of God to conceal a thing: but the honour of kings is to search out a matter.
3 The heaven for height, and the earth for depth, and the heart of kings is unsearchable.
4 Take away the dross from the silver, and there shall come forth a vessel for the finer.