If and when the Assyrians came into their land of Israel, the Israelites, would raise up against them. If these Assyrians treaded on their Israelite soil, they would have 7 shepherds, the full amount necessary, or 8 rulers, more than the perfect 7, to take care of the situation. They would, in fact, rule Assyria with a drawn sword. They would take over the land of Nimrod, another name for Assyria. They would be delivered from the Assyrians, if they tried to come into their land and walk across their border. This sounded like a strong warning, but were the Assyrians listening?
Isaiah has another strong warning about going to Egypt to get help. Those who go to Egypt will be cursed. They want help from horses, chariots, and cavalry horsemen because there are many strong ones in Egypt. However, they did not look to the Holy One of Israel. They did not consult with Yahweh before they set out on this mission. Besides many of this help would have been useless on the Israelite terrain.