What does Mark 7:2 mean?

To understand the context of this passage, some background information is necessary.

The Mosaic Law says that meat that has touched something unclean should not be eaten (Leviticus 7:19). If a food container is touched by a dead mouse or lizard, it and the food it holds is unclean (Leviticus 11:29–34). Food is very specifically divided in the Old Testament. There is that which is clean to eat, such as lamb or goat. Then, there is that which is unclean and must not be eaten, such as shrimp, or camel meat. If a person eats unclean food, the prescribed punishment is: nothing. The Mosaic Law does not give a punishment for breaking kosher laws (Leviticus 11).

Typically, a person would become ceremonially unclean because of touching a dead person or a non-kosher animal, or from having a discharge of some kind. As a result, they were not allowed to eat the peace offering (Leviticus 7:19–21). A peace offering is a voluntary expression of thanks wherein a person takes an animal or some grain to the temple and gives it to the priest. The priest burns some of it and gives the rest to the offeror and to the poor to eat. In order to break the law, the person would have to be knowingly unclean when they intentionally travel to the temple and perform the offering. They would then be cut off from their people (Leviticus 7:11–21).

When God gave Moses instructions to build the tabernacle, He included a large bronze basin filled with water. Aaron and subsequent priests are to wash their hands and feet before entering the tabernacle or approaching the altar to present a food offering (Exodus 30:17–21).

The scribes' and Pharisees' hand-washing tradition is based on Exodus 30, when it comes to priests. However, they disregard the intended application of Leviticus 11, regarding kosher laws. The religious leaders want a ceremonial cleanness that approaches that of a priest entering the temple, so they symbolically replicate the priests' hand-washing before eating food purchased at the marketplace. They wash their hands, and possibly the food, in case they have accidentally touched something or someone unclean. They expect the same diligence from other devout Jews.

Their thought process is that if their food is contaminated and made unclean, it will defile them when they eat it. "Defile" is from the Greek root word koinos. Literally, it means common or ordinary. In regard to the ceremonial law, it means unclean or profane. Jesus has a completely different interpretation. He says that what goes into a person's digestive system cannot make them unclean. Uncleanness comes only from a hardened heart—which the scribes and Pharisees have despite their legalism.