Various ideas have been offered as to the origin and appearance of the sa sign. Some of thought that it represented a rolled up herdsman's shelter or perhaps the papyrus life-preserver used by the Nile's boatmen. The hieroglyph appears in two forms. In the Old Kingdom, the lower section of the hieroglyph was undivided, while in the Middle Kingdom it was usually seperated.
The sa hieroglyph was a visual representation of the concept of "protection." It was often used in amulets and jewelry in hopes of rendering its protective powers over the owner. The sa was often used in compositions featuring other hieroglyphs such as the ankh, djed and was signs. It was also found used on magic wands or batons during the Middle Kingdom.
