This verse contrasts with the wonders of v. 19. The adulterous woman is not wonderful — she is brazenly unrepentant. She sins, wipes her mouth (as if she has merely eaten a meal), and declares her innocence. This is a portrait of a seared conscience — sin committed with such ease and lack of remorse that the person genuinely feels nothing. It is a warning about where unrepentant sin leads: to moral numbness.
Memory phrase: Sin must not be hidden.
Talk about it: Why is it dangerous to do wrong and feel nothing about it?
Prayer: God, keep my conscience soft. Help me feel sorry for sin.