PA: "If I Forget Thee, Oh Jerusalem" First Said by Crusader

Continuing its policy of denying Jerusalem's Jewish heritage the Palestinian Authority publicized the claims of an Arab researcher that the well-known ancient Hebrew psalm, "If I forget three, Jerusalem, may my right hand forget its skill," is not Jewish at all, the Israeli research institute Palestininian Media Watch reports.
The oldest surviving manuscript of the Ketuvim, or 'Writings,' which includes the Hebrew Psalms, is dated between 175–164 BCE. It contains Psalm 137.

PMW says it has documented the PA policy of denying Israel's history, no matter how ludicrous such denials prove to be, as a means of denying Israel's right to exist as a nation. The PA often denies a Jewish temple ever existed in Jerusalem, calling it "the alleged Temple," possibly agreeing with Nazi leader Goebbel's oft-quoted remark that if a lie is repeated often enough as if it is truth, it will be believed.

The following are the words of Palestinian researcher Dr. Hayel Sanduqa on PA TV, claiming that the Hebrew Bible's psalm was actually first said by a Crusader:

"[The Israelis] have acted to change Jerusalem's character. Even the expression (Psalm 137:5) 'If I forget thee, oh Jerusalem, may my right hand forget its skill. May my tongue cling to the roof of my mouth, if I do not remember thee.'

"This statement, said by the Frankish [Crusader] ruler of Acre shortly before he left, was borrowed by the Zionist movement, which falsified it in the name of Zionism," Sanduqa said.

The verse in question, from Psalm 137 of the Hebrew Bible, opens with the words: "By the rivers of Babylon, there we..
The psalm is a hymn expressing the yearnings of the Jewish people in exile following the Babylonian conquest of Jerusalem in 586 BC. The rivers of Babylon.

Psalm 137

1 By the rivers of Babylon we sat and wept
when we remembered Zion.
2 There on the poplars
we hung our harps,
3 for there our captors asked us for songs,
our tormentors demanded songs of joy;
they said, “Sing us one of the songs of Zion!”

4 How can we sing the songs of the LORD
while in a foreign land?
5 If I forget you, Jerusalem,
may my right hand forget its skill.
6 May my tongue cling to the roof of my mouth
if I do not remember you,
if I do not consider Jerusalem
my highest joy.