Matthew 23:28
So you also outwardly appear righteous to others, but within you are full of hypocrisy and lawlessness. The application of the whitewashed-tomb image to the Pharisees: the outward appearance of righteousness that conceals the hypocrisy and lawlessness of the inside. The lawlessness — anomia, the violation of the law — is what the Pharisees' law-keeping conceals: the very people who are known for their law observance are guilty of lawlessness in the things that matter most.