The ancient Egyptian horizontally-outstretched Arm with powerstick is a hieroglyph with the meaning of "force", or "power of action".
Power is obvious, but the origins may have also had references to magic, or the idea of driving-off evil spirits or omens.
A "sacred", or protected area is therefore created, by the action implied and used by the "Arm with Power stick".
The basic language equivalent of Arm with powerstick hieroglyph is 'djeser', or 'tjeser', meaning "holy", or "sacred".
"-(line 3) The second usage is the setup before the Rosetta Stone announces the 3-script Decree to be inscribed, and displayed.