The Star of David and the Book of Genesis, Chapter One, Verse One...

In the beginning, God created the Heavens and the Earth.

- Genesis 1:1

Notice how the Star of David is indeed the perfect symbol for which to represent all of God's Creation, not just Heaven (Triangle UP or Eye Above), or Earth alone (Triangle DOWN or Eye Below), but the entire continuum (both Heaven AND Earth) initially created by God at the beginning of Time. Seems to me, the Star of David is indeed referenced with the very first sentence found in the Judeo/Christian Bible. It is one of the reasons why the Catholic Church still tends to call the hexagram the Star of Creation, or Creator's Star.