以其人之道，还治其人之身
yǐ​qí​rén​zhī​dào​huán​zhì​qí​rén​zhī​shēn

to give someone a taste of their own medicine

以其人之道，还治其人之身 以其人之道，還治其人之身 yǐ​qí​rén​zhī​dào​huán​zhì​qí​rén​zhī​shēn
to give someone a taste of their own medicine
To use an opponent's own methods to obtain retribution; to get revenge by playing someone back at their own game.