I'm not familiar with that prediction. I am, however, familiar with the false prophecies the writers of the Gospels attributed to Jesus. According to them, he foolishly predicted the end of the world would come before that generation had died off. One of the amazing things about human nature is how durable religious delusions tend to be in the face of unmistakable disproof. If I predict the DOW will rise 10% tomorrow and it doesn't, my credibility on the topic will be shot. But if I claim to be the Son of God and I predict the world will end within a generation, and it doesn't, there's a good chance my humiliating failure will just increase people's faith in my silly claims. It's strange, but that's the religious mindset for you.