Let me give you my own experience of the events, though I think it might make explaining the recent events even tougher.
Basically, at about the same time Trump made his speech, we started getting panicked notifications from our media that the IDF is "preparing" for something and that an Iranian attack is imminent. It seems like the Israeli bion detected the intentions of the Iranians, and around that time, we got first reports of explosions near Damascus. When the fog cleared, we've discovered that the Israeli airforce destroyed a bunch of missiles aimed directly at Israel. If I recall it correctly, there was another bunch of missiles destroyed before they could be fired later on, and then a barrage they actually managed to fire at the Golan Heights, but it fell entirely flat- some hit open plains, others were intercepted by the Iron Dome missile defence system. Israel retaliated, as you wrote in the OP. Overall, this seemed to have been a massive military embarrassment for Iran, failure after failure as Israel was a step ahead every time.
As to why they did that... TF's explanation is interesting, but I believe it's incorrect. The missiles weren't fired by the Iranian army directly, but by the
Quds Force, an Iranian force operating in the levant. Their commander, Qasem Soleimani, got some attention from our media and was apparently "in command of the Iranian efforts to retaliate against Israel". So, in light of this wording used by our media and of the fact he's still very much fine, my belief is that this is not Soleimani's personal decision, but orders from above. The reason? Might be an attempt to soil Trump's announcement, perceived as a victory for Israel. Think about it- Bibi receives his wishes, the President of the United States withdraws from the agreement and imposes new sanctions... and then dozens of missiles fall on Israeli territory, potentially killing civilians or military personnel. This could've sent a powerful message- we're here, we're powerful, and we don't fear you. Israel is the only logical target for it, given that attacking the U.S. would have disastrous consequences for the regime. Fourtunately, it fell heavily flat, and was instead a success for Israel.
