What does the statement Hateful to you as the gates of Hades is that man who hides one thing in his heart and speaks another mean?

This statement from Homer's "Iliad" emphasizes the disdain for individuals who are deceitful and hypocritical, concealing their true thoughts and intentions while expressing false ones. It conveys the idea that genuine honesty and integrity are highly valued, and duplicity is seen as despicable, akin to the gates of Hades, which represent the underworld in ancient Greek mythology.