Part of the ongoing Verse Quick Reference project.
2Sa 14:20 In order to change the course of things your servant Joab did this. But my lord has wisdom like the wisdom of the angel of God to know all things that are on the earth.”
An often ignored verse, 2 Samuel 14:20. In context, Joab wants to convince King David to forgive Absalom. He sends a woman to David in order to do the convincing. She begins her speech with flattery. King David, she says, knows “all things that are on earth”. Naturally, this should be taken in a hyperbolic sense.
But the phrase is interesting. Elsewhere, other kings are said to know everything. The idea likely being forwarded is that the king has wide-ranging power. Their access to information is above virtually anyone else.
The same phrase, if applied to God, would be taken as Platonic Omniscience by Negative Theologians. God knows all that can be known, instantly and inherently. But the phrase is instead applied to two creatures, David and the angel of God.
The angel of God could be Yahweh (there is precedence in the Bible for this), but this seems to be applied to creatures as well. King David, himself, is said to be an “angel of God” five chapters later:
2Sa 19:27 And he hath slandered thy servant unto my lord the king; but my lord the king is as an angel of God: do therefore what is good in thine eyes.
That this type of omniscience, a knowledge of all things on Earth, would be applied to angels and man, shows the extent of hyperbolic phrases of this type in the Bible. It also is a clear example of this type of speech not being meant in a Platonic sense.
God is Open 
Is David omniscient?
Thus, what do we make of something a Bible character says on any topic?
John 9:31 (NRSV)
31 We know that God does not listen to sinners, but he does listen to one who worships him and obeys his will.
Act 4:27-28 (NRSV)
27 For in this city, in fact, both Herod and Pontius Pilate, with the Gentiles and the peoples of Israel, gathered together against your holy servant Jesus, whom you anointed, 28 to do whatever your hand and your plan had predestined to take place.
I think all these statements are generalizations/hyperbolic and allow exceptions. I don’t think why of these speakers were trying to communicate absolute and inflexible metaphysics.
I agree.