An interesting tangent:
The six pointed star is not truly a Jewish symbol either. It is typically referred to as the “Star of David” and that discription is actually far more accurate. The star was the sign or his royal house, much like a coat of arms.
There are two explanations I have heard as to how the star become David’s symbol
The flower associated with his rule has six petals with a dot in the center of each. Connect the dots, get the star symbol. Can’t remember the name of the flower nor why it is associated with the house of David…
The hebrew letter for “D” (Daled) in the old hebrew script (not the hebrew characters used today) is shaped like a triangle. In hebrew, vowels are typically omitted so David’s name would be written “DVD”. One can imagine David taking the first and last letter as his initials (no last names back then), inverting the second Daled on top of the first, getting a six pointed star, and using it as a royal symbol.
One other point, The hebrew phrase most often translated as Star of David, “Magen David”, literally means “The Sheild of David” which would typically have been painted with a personal symbol for easy identification in battle.
Can anyone confirm either of these hypotheses?
BTW The closest thing to a ‘religious’ symbol in Judaism would have to be the Menorah (a six branched candelabra used in the Temple in Jerusalem - a image of which can be seen on the Arc of Titus in Rome which commemorates the capture of Jerusalem). Ironically, the Israeli government chose the star for the flag specifically because it had no religious content (they were good socialists) but as a sop to the religious zionists, chose the Menorah as the symbol of the Knesset (the Israeli Parliament).