Iran hasn't said it wants Israel destroyed. Their president said he expects the political entity that Iranians consider to be an aggressive apartheid regime to be dismantled at some point in the future. There is a big difference between these two things. Keep in mind that the term "Israel" for many people in that region doesn't have anything to do with the landmass that Israel is sitting on, or even the general population of that country, but refers specifically to the regime that holds power there. To the Iranians, that regime is what they would term the Zionist regime. They want that regime to go away. They don't, however, want the people of Israel to be killed.

In Iran they say "death to" anything they don't like. Including traffic. It's a common expression there that really has nothing whatever to do with an intention to actually kill anyone.