This design is based on the Flag of Palestine that appeared in a 1934 illustrated French dictionary. The official flag of the Jewish homeland at that time was actually a variation on the Union Jack, because Palestine--which includes the modern day states of Israel and Jordan--was under British control. (The name Palestine derives from "Syria Palaestina," a designation given to the Land of Israel by Roman invaders as a means of humiliating the indigenous Jewish population. We guess not much has changed thgere!) Nevertheless, designs of this type were in use by the Zionist movement, which included the Jews who had never left, and others returning to Israel from thousands of years of exile.
Although the Jewish Palestine Banner was not officially adopted, it still predates the concept of "Palestinian" as a national identity. So there's that.
Celebrate the Israeli occupation of Israel unironically, with the Jewish Palestine Flag!