Matthew 23:27

"Woe unto you, Scribes and Pharisees, hypocrites! You are like white-washed sepulchers. They look beautiful without, but within they are filled with dead men's bones and all rottenness.

Luke 11:44

"Woe unto you! for you are like the tombs which are hidden, and men walk over them unsuspecting."

Treasury of Scripture Knowledge

Summary

And whosoever toucheth one that is slain with a sword in the open fields, or a dead body, or a bone of a man, or a grave, shall be unclean seven days.

Bible References

A grave

Matthew 23:27
"Woe unto you, Scribes and Pharisees, hypocrites! You are like white-washed sepulchers. They look beautiful without, but within they are filled with dead men's bones and all rottenness.
Luke 11:44
"Woe unto you! for you are like the tombs which are hidden, and men walk over them unsuspecting."