The exact quote is:
Imam goft een rezhim-e-ishghal-e-qods bayad az safeh-ye-ruzgar mahv shavad
Which, based on the Farsi I know literally translates to:
The Imam [Khomeni] said, the regieme occupying Jerusalem should disappear from the pages of history.
Again, no military threat.
The issue isn’t whether his statement was eloquent and diplomatic…it’s whether it constitutes a direct threat against Israel. Such undiplomatic statements are fairly common…whether its Rahul Gandhi gloating about how his family is personally responsible for the Civil War and subsequent break-up of Pakistan, or Hugo Chavez babbling about how humankind has no future if American hegemony continues unchecked. These are statements of empty rhetoric, meant to rile up crowds and win public support among the asses of the masses. They generally are not construed as direct military threats, and certainly can not be used as justification for any sort of direct intervention.
But while we’re on the topic of direct military threats, it seems as though Israel already has developed plans for nuclear strikes against Iran:
Revealed: Israel plans nuclear strike on Iran - Times Online
That to me seems like a much more imminent threat than quoting Khomeni in some speech.