* **you are like unmarked graves that people walk over without knowing it** - This is a simile. The Pharisees were like unmarked graves because they looked ceremonially clean, but they caused people around them to become unclean. This point of similarity is somewhat more clear in the UDB. (See: [[en:ta:vol1:translate:figs_simile]])
* **unmarked graves** - These graves were holes dug in the ground where a dead body was buried. They did not have the white stones that people normally place over graves so that others would see them. When people walked over a grave, they would become ceremonially unclean.