It is a way to call Jesus, although the phrase is used to refer to other characters of the seventies Version of the Bible in Greek. It comes from 965; 7985; 959; 962; 964; 959; 965; 945; 957; 952; 961; 969; 960; 959; 965; (uios tou anthropou "Son of man") and seems to be an expression of humility for the son of God, as Messiah is also son of man. It is also the title of songs, movies, novels, journalistic notes, all alluding or paraphrasing the original meaning.