The Ancient Egyptian Mat hieroglyph, (originally for a stool), and later the Stool hieroglyph, Gardiner sign listed no. Q3 originally was the stool's rectangular mat; later it became the representation for the stool itself.
The Mat or Stool hieroglyph is used in the Ancient Egyptian language hieroglyphs for the alphabetic consonant letter 'p'.
The learned Egyptologist are looking Q3 hieroglyph as a stool or stool's rectangular mat, which has language value of 'p i'. Above rectangular glyph is based on Sanskrit single letter's word "i ('p' without sound of 'ee' as in perfect)" and its meanings are 'guarding, protecting, ruling, drinking'. One who protects or guards.
Above pictograph shows four sides fencing for 'protecting or guarding'.