The earliest I can find is Agence France Press at 9:46 AM GMT on October 26. The headline is "Israel should be 'wiped off the map': Iran president"
I found the article via Lexis-Nexis. You can see headlines only (not full text) on the AFP website.
Also, the New York Times (Oct 27, "Iran's New President says Israel Must be "wiped off the map"") says it was reported by ISNA (the Iranian Student News Agency). The ISNA website is all in Arabic, so I don't know if they are also responsible for the English translation.