Jesus spoke aramaic i quess, no matter what aionon actually means, as far as i know there was no word meaning eternal in the sense of endless in ancient hebrew or aramaic, so Jesus might have said olam - it's obvious that olam doesn't mean eternal in many places in the Old Testament, where the septuagint translates aionon, i think this might a good argument that Jesus might have never used a word meaning eternal in his mother tonque, what do you think about?