What king, going to make war against another king..? — Here also there may have been a side-glance at contemporary history. The Tetrarch’s divorce of his first wife had involved him in a war with her father Aretas, an Arabian king or ethnarch (see Note on Luke 3:14), in which his army was destroyed, and the Jewish historian sees in this the commencement of all his subsequent misfortunes (Jos. Ant. v., 18:5, § 1).
In the spiritual interpretation of the two parables, the tower reminds us of the house in Matthew 7:24-27, and so stands for the structure of a holy life reared on the one Foundation; the warfare brings to our remembrance the conflict described in Matthew 12:29. Here it stands partly for the conflict which every Christian carries on against sin, the world, and the devil, and of which we should take a clear estimate before we enter on it, partly for the greater war on which Christ Himself had entered, and of which He too had counted the cost — that being, in His case, nothing less than the sacrifice of His own life.