This term refers to vessels or containers made of copper or bronze, commonly used for cooking, storage, and serving in the ancient world. Mark mentions them when describing the Pharisees' ritual washing practices: they observed traditional washings not only of hands and cups and pitchers, but also of 'copper vessels.' The detail illustrates the extent of ritual purity concerns, extending beyond person and food to include the very utensils used in preparation and serving. Bronze or copper vessels were durable and valuable, yet still required purification according to traditional practice.