Charles Ellicott Commentary Luke 14:31

"Or what king, as he goeth to encounter another king in war, will not sit down first and take counsel whether he is able with ten thousand to meet him that cometh against him with twenty thousand?" — Luke 14:31 (ASV)

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. The Jewish historian sees this as the beginning of all his subsequent misfortunes (Josephus, Antiquities, Book 18, Chapter 5, section 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 built on the one Foundation. The warfare, similarly, calls to mind the conflict described in Matthew 12:29.

Here, this warfare stands partly for the conflict that every Christian carries on against sin, the world, and the devil—a conflict for which we should clearly estimate the cost before we enter into it. It also stands partly for the greater war on which Christ Himself had entered, and for which He too had counted the cost—that cost being, in His case, nothing less than the sacrifice of His own life.