Teresh was one of two royal officials who plotted to assassinate King Ahasuerus before Mordecai exposed the conspiracy.
Biography
Esther 2 says Bigthan and Teresh, two of the king's eunuchs who guarded the threshold, became angry and sought to lay hands on Ahasuerus. Mordecai learned of the plot and informed Esther, who reported it to the king in Mordecai's name. Investigation confirmed the charge, and the conspirators were executed; the event was recorded in the royal chronicles.
Biblical Significance
Teresh's failed conspiracy becomes providentially important because Mordecai's unrewarded loyalty is later rediscovered at the precise moment that reverses Haman's plot.