How do you reconcile that statement regarding a 1919 document with the 1917 Balfour Declaration? Who where the people in the "existing non-Jewish communities in Palestine" if not Palestinians?
The Balfour Declaration
Dear Lord Rithchild,
I have much pleasure in conveying to you, on behalf of His Majesty's Government, the following declaration of sympathy with Jewish Zionist aspirations which has been submitted to, and approved by, the Cabinet.
His Majesty's Government view with favour the establishment in Palestine of a national home for the Jewish people, and will use their best endeavours to facilitate the achievement of this object, it being clearly understood that nothing shall be done which may prejudice the civil and religious rights of existing non-Jewish communities in Palestine, or the rights and political status enjoyed by Jews in any other country.
I should be grateful if you would bring this declaration to the knowledge of the Zionist Federation.
Signed: Arthur James Balfour
Whereas recognition has thereby been given to the historical connection of the Jewish people with Palestine and to the grounds for reconstituting their national home in that country
An appropriate Jewish agency shall be recognised as a public body for the purpose of advising and cooperating with the Administration of Palestine in such economic, social and other matters as may affect the establishment of the Jewish national home and the interests of the Jewish population in Palestine, and, subject always to the control of the Administration to assist and take part in the development of the country.
The Zionist organization, so long as its organization and constitution are in the opinion of the Mandatory appropriate, shall be recognised as such agency. It shall take steps in consultation with His Britannic Majesty's Government to secure the cooperation of all Jews who are willing to assist in the establishment of the Jewish national home.
The Administration of Palestine, while ensuring that the rights and position of other sections of the population are not prejudiced, shall facilitate Jewish immigration under suitable conditions and shall encourage, in cooperation with the Jewish agency referred to in Article 4, close settlement by Jews on the land, including State lands and waste lands not required for public purposes.
The Administration of Palestine shall be responsible for enacting a nationality law. There shall be included in this law provisions framed so as to facilitate the acquisition of Palestinian citizenship by Jews who take up their permanent residence in Palestine.
As to a particular type of Arab, a "palestinian", I'll take the PLOs definition, since they coined it.
"The Palestinian people does not exist. The creation of a Palestinian state is only a means for continuing our struggle against the state of Israel for our Arab unity. In reality today there is no difference between Jordanians, Palestinians, Syrians and Lebanese. Only for political and tactical reasons do we speak today about the existence of a Palestinian people, since Arab national interests demand that we posit the existence of a distinct 'Palestinian people' to oppose Zionism."
PLO executive committee member Zahir Muhsein on March 31, 1977
Arabs, Turks, Beduin and Druze. Palestinian is a regional geographic moniker, like "New Englander" which includes all the people living there. It was not an ethnic or national identifier.