By A.W. Tozer once wrote:
God knows instantly and effortlessly all matters. And because God knows all tings perfectly, He knows no one thing better than any other thing, but all things equally well. He never discovers anything. He is never surprised by anything. He never wonders about anything.
This is merely a rephrasing of Psalm 147:5b. In more human-like terms, Proverbs 15:3 informs us that God sees everything.
There is two sides to the significance to us of this truth about God. First, if you are righteous and blameless, then God will vindicate you one day. But the flip-side is that if you are hiding sin, don’t fool yourself, justice will come in due time; God knows.