Hamas isn’t talking about the “normal routine” that Israel and Hamas go through all the time with the rocket attacks. This is a very long-standing routine.
What Hamas is referring to is if Israel does something different, outside of the retaliation for rocket attacks. Now the problem here is that Hamas for the first time - is supposed to be able to hit Tel Aviv, and that would be a lot more serious than the rockets they normally fire. Hamas is holding these in reserve to really inflict some serious damage!
It’s strange; in some of your posts (like that one, for example), you sound like you’re rooting for Hamas, and really hoping and praying that Israel treats them with kid gloves.