How did John Know of the River of Blood?

Here, we dive into the fulfilled prophecy of John and the mentioned bleed rising to the horse's bridle. The fulfillment of this prophecy is so extreme that many people have believed that it was an exaggeration or that it had to do with blood flowing to a location in Israel called "The Horse's Bridle". However, if you are a student of history, you will easily see that there are no special circumstances or mental gymnastics needed to see that the prophecies in God's Word are true prophecies.