Answer:
1. The author includes relatively few Old Testament quotations--only half as many as in Matthew.
2. He described such Jewish customs as the washing of hands (7:2-3) and explained the value of two mites (12:42).
3. Mark also gave a geographical description of the Mount of Olives (13:3).
4. Mark was also careful to tell when the Passover lamb was killed (14:12) and when the preparation was made (15:42). No one who took part in Jewish culture would need such explanations.
