As usual Duterte’s exaggeration shows he is often over the top.
As opposed to turning all of Gaza into a cemetary, I, if I were Israel, would insist all residents of Gaza must leave Gaza, as they have shown they will never live in peace with Israel, and then I’d occupy and annex Gaza to Israel proper, forever.
>...all residents of Gaza must leave Gaza...
Additional clause needed. They may NOT go to the West Bank and West Bank Palis can't repopulate Gaza. Collect fingerprints and other bio identifiers on their way out of Gaza to aid enforcement of their lifetime exclusion from Israel. And zero allowed in US (ideally or Europe) as refugees. Give them all to the Muslim majority world. They created the problem by refusing them initially and by keeping them refugees. They, only, should have to take the responsibility for them now.
Supposedly there are a couple thousand Christian arabs in Gaza. Might consider excluding them from the expulsion and allowing immigration of persecuted Christians from other middle eastern countries to help fill the void.