Where do they come up with crap like this?
It's their own propaganda.
http://en.wikipedia.org/wiki/Flag_of_Israel
Claims of "Nile to Euphrates" territorial ambitions
It has been alleged by some groups that the blue stripes actually represent the rivers Nile and Euphrates, which some Zionist thinkers (such as Avraham Stern and Israel Eldad) have claimed as the boundaries of Eretz Yisrael, the land promised to the Jews by God. They claim that this flag thus "secretly" represents the desire of Jews to conquer all of the land between the Nile and Euphrates rivers, which would involve conquering and ruling over much of Egypt, all of Jordan, and some of Syria and Iraq.
This allegation that Jewish territorial ambitions include all the land from the Nile to the Euphrates has been popular in Arab literature since the 1940s. Amin al-Husayni, former Mufti of Jerusalem stated:
The Palestine tragedy is unequaled in history. The Zionist imperialistic plot against Palestine was most inhumane and base. World Judaism plans to take over most of the Arab countries to fulfill its so-called historical dream of a homeland between the Nile and Euphrates. The Imperialist Jewish plot is not aimed at Palestine only...
Yasser Arafat in a September, 1988 interview with Playboy Magazine also made the allegation and in 1997, the Iranian parliamentary speaker Ali Akbar Nateq Nuri accused the Jews of attempting to live out a "Nile-to-Euphrates dream."
Both Zionist and anti-Zionist authors have debunked the claim that the stripes on the flag represent territorial ambitions. In his article "Imperial Israel: The Nile-to-Euphrates Calumny" in the March, 1994 Middle East Quarterly Daniel Pipes notes "In fact, the blue lines derive from the design on the traditional Jewish prayer shawl."[3]. Persistent critic of Israel and Zionism Israel Shahak is more explicit. In his The Zionist Plan for the Middle East he states
A good example is the very persistent belief in the non-existent writing on the wall of the Knesset of the Biblical verse about the Nile and the Euphrates. Another example is the persistent, and completely false declarations, which were made by some of the most important Arab leaders, that the two blue stripes of the Israeli flag symbolize the Nile and the Euphrates, while in fact they are taken from the stripes of the Jewish praying shawl (Talit).
Saqr Abu Fakhr, an Arab writer, has also spoken out against this idea. In his article "Seven Prejudices about the Jews" (published in the London-based pan-Arab daily Al-Hayat, November 12,13,14) he demonstrates that the "Nile to Euphrates" claim is one of seven popular misconceptions and/or myths about Jews which, despite being unfounded and having abundant evidence refuting them, continue to circulate in the Arab world.