He bases this on UNGA resolution 194, which the Arabs love to misinterpret as saying that any Arab whose ancestors came from Palestine has the right to move into Israel, forever.
Notwithstanding the fact that General Assembly resolutions have no legal force, the constant reference to that resolution by the Palestinian Arabs is the height of hypocrisy.
If they believe to strongly that UNGA 194 must be adhered to by Israel, then they must also believe:
- Jerusalem will never be the capital of "Palestine" because UNGA 194 says it is part of a separate territory that must be under UN control - including much more of "Palestine." than of Israel. Many Arab towns, and even all of Bethlehem, would not be part of "Palestine."
- Mount Scopus would be part of Israel proper.
- Descendants of Jews who were expelled from Gush Etzion. the Old City and other areas would be allowed to live in their ancestral homes. UNGA 194 just refers to "refugees," not "Arab refugees."
- Free access to Jewish holy places in Judea and Samaria would have to be enforced.
Keep in mind that no Palestinian Arab leader is anxious for millions of Arabs now living in Lebanon, Jordan, Syria and elsewhere to "return" to "Palestine." Unlike the Zionist in the 1940s and 1950s who happily took in hundreds of thousand of Jews from the Diaspora, Palestinian Arab leaders are in no rush to help out their brethren who have been rotting away in camps for decades. To them, the descendants of "refugees" exist for only one purpose - to destroy Israel by "returning." Besides that, they couldn't care less about them.
Their hypocrisy - and their goal in erasing Israel - cannot be more transparent. And the world cannot be more blind as to their goals, even when they say it explicitly.