Was the supernatural common whenever God dealt with Israel in the land?
Yes. The pattern is that whenever God dealt with Israel in the land, the supernatural was commonplace. Examples include the plagues in Egypt and the opening of the Red Sea, both supernatural events under God's control. This supports the supernatural phenomena described in Revelation.
Les explains that this is God dealing primarily with the nation of Israel, as he showed in closing remarks. Jeremiah called it the time of Jacob's trouble. Les points out that whenever God dealt with Israel in the land, the supernatural was commonplace. For example, beginning when Moses went into Egypt, the plagues were supernatural events under God's control. The opening of the Red Sea was supernatural. This historical pattern supports the supernatural events in Revelation, such as the great earthquake, the sun becoming black as sackcloth, and the moon becoming as blood, which may result from volcanic eruptions and atmospheric pollution rather than God directly blackening the sun.