Ver. 18. The motive of this procedure on God’s part has already been indicated in βουλόμενος, but now it is more fully declared. ἵνα διὰ δύο … ἐλπίδος “that by two immutable things in which it is impossible for God to lie, we may have a strong encouragement, who fled for refuge to hold fast the hope set before us”. The two immutable things are God’s promise and His oath. It is impossible for God to break His promise, impossible also for him to falsify His oath. Both of these were given that