"Son of man", "son of Adam", or "as a man", are phrases used in the Hebrew Bible, various apocalyptic works of the intertestamental period, and in the Greek New Testament. In the indefinite form ("son of Adam", "son of man", "like a man") used in the Hebrew Bible, it is a form of address, or it contrasts humans with God and the angels, or contrasts foreign nations (like the Sasanian Empire and Babylon), which are often represented as animals in apocalyptic writings (bear, goat, or ram), with Israel which is represented as human (a "son of man"), or it signifies an eschatological human figure.
The phrase is used in its indefinite form in the Septuagint, Biblical apocrypha and Pseudepigrapha. The Greek New Testament uses the earlier indefinite form while introducing a novel definite form, "the son of man."