I love the imagery of the prophets! On “that day”, which is a reference to the day that the Lord will return as conqueror and judge, Satan will be thrown for good. There is a sense in which he is bound now, as Christ “bound the strong man” when he came 2000 years ago. But there will be finality to Satan’s downfall when Jesus returns.
In that day the Lord with his hard and great and strong sword will punish Leviathan the fleeing serpent, Leviathan the twisting serpent, and he will slay the dragon that is in the sea. (Isaiah 27:1)
McCheyne’s Bible Reading Plan: Num 35, Ps 79, Is 27, 1 Jn 5