Final answer:
Walls can provide protection and regulate the flow of people and goods.
Step-by-step explanation:
The document you mentioned suggests the idea of a wall. While it is unclear which wall is being referred to without the document, I can provide you with general benefits of walls in historical contexts. Walls can provide protection to a city or nation by acting as a barrier against invasions. They can also define borders and regulate the flow of people and goods.
One example of a historical wall is the Great Wall of China, which served as a defensive structure to protect against invasions. Another example is the Berlin Wall, which was built to separate East and West Berlin during the Cold War period and prevent people from escaping from East Germany to West Germany.
It's important to note that the benefits of walls can vary depending on the specific context and circumstances.