The Hebrew words under the flag say: "Be Strong And Resolute"
Lauren Gelfond wrote in 2003 a nice article titled Star Light, Star Bright, where she tells about the exaggerated reactions of people to the Magen David. Among other things she says:
Online, a writer argues that: “Those two blue stripes on the Israeli flag represent the Nile River in Egypt and the Euphrates in Iraq. With the so-called David star in the middle, the message is: The land between these two rivers belongs to the Jews."