Dr Maurice Casey is one of but a handful of Biblical scholars in the world who is fluent in Biblical Aramaic, the language Jesus spoke. (Sorry KJV fans but Jesus did not speak English). The term Son of Man is not really normal Greek or natural sounding English, but it is good Aramaic. So what would Aramaic speaking Jews have made of Jesus when he referred to himself as bar nash? What did it mean? Here is a highly informative discussion of the language that Jesus actually spoke. There are a few surprises..
Maurice Casey, Jesus of Nazareth: An independent historian’s account of his life and teaching, page 358 onwards. Casey is Professor of New Testament Languages and Literature at the University of Nottingham, UK.