One way to work this out, is to remind ourselves not to limit God by time. We are so accustomed to think of time linearly. God, however, is outside of time. He can arrange Old Testament events in such a way based on what He already knew about New Testament events. In fact, far more than that, knowing in the eternal instant all the choices of all the angels and humans, He in one instant arranged all history in such a way to bring His Plan to fuition for all, always without trespassing our freedom of choice.