1 Samuel 16:7 But the Lord said to Samuel, “Do not look at his appearance or at his physical stature, because I have refused him. For the Lord does not see as man sees; for man looks at the outward appearance, but the Lord looks at the heart.”
When God sent Samuel in to anoint the future King of Israel He told Samuel that there was a big difference between what God sees and what man sees.
Israel had chosen Saul as king because he was a mighty man, tall and powerful and probably very imposing. Most people look up to powerful people and listen to them; so man’s choice is not always right.
God knows what is going on inside people’s hearts and minds and so can make a perfect choice rather than a good guess as we do!