Luther on Abraham’s night terror in the concluding verses of Genesis 15:

Moreover, it is also the purpose of this passage to teach us what God’s nature is. He is indeed the Deliverer and Liberator from death. But before He delivers, He destroys; before He makes alive, He plunges into death. For He is wont to act in this way “so that out of nothing He may make everything” (Heb. 11:3).