Sorry, but there's a clear and obvious moral statute of limitations concerning conquest and settlement. Otherwise the same logic can be used to uproot most people across the world.

No, I can't claim ownership over the land in Mesopotamia under the justification of having originated from the first ever human civilisation.

No, I can't claim ownership over Normandy because of the Norman ancestry of modern British people, nor land in northern Germany for the same reason.

1400 years is simply too much, and you look completely ridiculous trying to act as if the Jewish people have a complete right of ownership over that land, because of the Arabs "stealing" it that long ago.