The Davids Star was actually used in many islamic banners prior to 1948, i think it means strength or power, or something along these lines. Its based on David defeating the Goliath (taken from the koran, can't recall wich surah though).
This is true.

Apparently some guilds in the Islamic world were using the star as a symbol of strength or power. Syria was known for quality steel and the excellent swords made there. The blacksmiths in Damascus formed a guild, and began engraving their swords with the star, which became known as the 'Star of Damascus.' Because the swordmakers in Damascus were so renknowned for their skill, the Star of Damascus became recognized as a symbol of quality worksmanship on any sword. Being before the time of copyrights, other swordmakers all over the world copied the symbol and used it on their own swords. Basically it was a marketing ploy, as the Star of Damascus had become associated with quality worksmanship.

The U.S. Marine Corps NCO sword today also has an star engraved on it. It is often mistaken for the Jewish star of David, but it is actually the Star of Damascus. The ceremonial NCO swords are replicas of the original, which also bore the Star of Damascus. The original was not made in Damascus, it was made by an American company, which had appropriated and revived the old symbol.