“And the Lord was sorry that He had made man on the earth, and He was grieved in His heart. So the Lord said, “I will destroy man whom I have created from the face of the earth, both man and beast, creeping thing and birds of the air, for I am sorry that I have made them.” (Gen 6:6, 7)
Here are two of the primary verses that open theists use to assert that God does not know the future, independent choices or decisions of men. The rationale goes something like this: If God was sorry that He made man upon the face of the earth then He clearly did not see the event coming for which He was sorry. After all, why would He say He was sorry about something He knew was going to happen, and something that was the result of His doing?