"And even in the matter of the envoys of the rulers of Babylon, who sent to him to inquire of the wonder that had happened in the land, God left him alone only to test him, that He might know all that was in his heart," (2 Chron. 32:31).
In 2 Chron. 32:31, Hezekiah was prospering and God "left him alone only to test him, that He might know all that was in his heart." This verse, however, cannot be claimed by open theists to show that God learns. The verse says that God tested him to know all that was in his heart. Even in open theism, God knows the present exhaustively. So, how could it be that God would test Hezekiah to see what was in his heart when God knows all present things exhaustively and could just look into his heart to see what was there? Obviously, there is more going on here than meets the eye.
God routinely tests people, not so He will learn what they will actually do, because God knows all things (1 John 3:20). Instead, it is usually for the strengthening and purification of the faith of God's people (or an individual) so they might learn and grow through the test. Furthermore, God speaks to them in discovery terms so they might hear and know that God "now will use them" according to His purpose. Testing verses are also related to God's anthropomorphic expression where God speaks in human terms, in human ways, as He reveals Himself to and through people.