Yes. They say that shit, and the lower ranks repeat it, and it gets done. Clearly the orders get relayed and implemented. What more proof do you need? It is nothing new that people lie when committing crimes to cover their asses. But you can actually look at what they’re doing to figure which of these statements is actually true: “We do everything in accordance with international law!” or “We will starve and bomb them until they leave or die!”.
Israel almost never punishes any of their own soldiers, or even admits any wrongdoing, even in pretty clear-cut cases. Arguing that Israeli courts are going to stop the genocide is completely delusional. They haven’t done shit so far, and they have no track record of doing anything. That’s because this is not about individual war crimes, this is a systemic policy implemented and supported throughout all institutions of the Israeli state, coming from the very top. You just do not want to see it.