The people did as God told them to do and they experienced a great victory. It would have been tempting to keep the horses and chariots for future military use, but God wanted them to depend on him.
There is nothing wrong with using the things God has given us, but it is important not to trust those things instead of God. When we trust in our money, insurance policies, jobs, or government, we are trusting in things that can let us down. Only God’s promises give security and will carry over into eternity.