legality doesnt mean much when youre talking about unwanted colonialist rule
Are you suggesting that no real estate sales were valid while the British were in charge? What about when it was the Ottoman Turks that were colonizing it, should we ignore all property rights from that period, too? How many local people need to object to immigrants owning property before you support violence against the immigrants and denial of their property rights?
And 100% all of this stems from zionism. They had to live in the holy land, people were there already, so they killed or exiled hundreds of thousands of people from their homes.
The 1948 UN borders had Jerusalem in neither state's territory. Palestine went to war over it. If they lose the holy land to Israel, this is why.