The text does not mention a wall around the inner courtyard. This may be because the inner court stood higher than the outer court. It was raised by another eight steps, which may have been about 2.4 meters (about 8 feet) high.
If there were no wall, there may have been a free-standing archway (an open structure shaped like an arch). This design would allow people to see what was happening inside. At the same time, the height would prevent anyone from stepping into the sacred area by accident.
Another possibility is that the text simply does not mention the wall. The writer may have left out that detail, even if a wall was present.