Bock explains: Multiple attestation argues that if a saying, teaching, or theme is attested in multiple sources, then it has a better chance of being authentic, that is, of going back to authentic events in the life of Jesus. … The rationale here is that the more widely distributed an idea is across the independent levels of tradition, the more likely it is to be old and reflective of actual events. The independence of the sources from one another means that no one of them created this event, but