There was once a small city with a few men in it, and a mighty king attacked it, besieging it and building strong siege works against it.
Later King Ben Hadad of Syria assembled his entire army and attacked and besieged Samaria.
This is what I also observed about wisdom on earth, and it is a great burden to me:
For the days will come upon you when your enemies will build an embankment against you and surround you and close in on you from every side.
However, you may chop down any tree you know is not suitable for food, and you may use it to build siege works against the city that is making war with you until that city falls.