How can one cut a square hole in wood by hand?

To cut a square hole in wood by hand, you can use a combination of tools such as a saw, chisel, and mallet. Start by marking the outline of the square hole on the wood. Then, use a saw to make straight cuts along the lines. Next, use a chisel and mallet to remove the wood within the marked area, working carefully to create clean edges. Repeat this process until the square hole is the desired size and shape.