If their goal is to wipe out israel from the map and that attacking them would allow them to do that, why would they warn against attacking them? Wouldn't Israel attacking them help them accomplish that goal? then why the warning? sounds to me like the opposite is true and they are posturing to look tough.
U.S., allies conduct 20 air strikes in Syria and Iraq against ISIS, says U.S. military (Reuters)
from the article: Iran army general: Attacking us would be suicidal