You both think it likely that he accidentally wrote "We must not expel the Arabs … " and then crossed out the "not."

I think that most unlikely!

You both think that ""the Israeli regime is attempting to ethnically cleanse Israel of Palestinians."

OK, then tell me why you do and why I should believe it.
Ancient and dubious quotes from the long dead are not evidence of the current policy.

Have any Arabs been cleansed out of Israel?
Evidence please.
Is it being attempted?
Evidence please.