That's because he never said "wipe off the map".
Read the above for a full translation, and look for your own sources if you don't believe it.
If you really want to be sure, you can even get a Persian dictionary and translate it word for word yourself.
Does not really matter. The statement was perceived as a threat to the Israeli government. The very statement that 'Even Iran can be wiped off the map', suggest that they think of it as a threat to national security.