Send them thousands of bunker busters. One for each of the rockets they sent into Israel. If a few accidentally drop in Syria and Iran, who cares. Accidents will happen as they say.
I remember when that was developed during the first Gulf War. I was working at TI and everyone in the company was told to give 100% support to anyone in the group supporting this bunker buster bomb. I bomb was in the air headed to the ME 13 days after it was requested.
(originally made from surplus Army canon barrels, during the 1st Gulf war, according to a close friend of mine who was a part of the team which developed it... Trickiest part is the fuse--which must go off only when it senses open space (not solid concrete)).