“the guards covered Haman’s face.” The Hebrew text simply reads, “they covered Haman’s face,” but the people reading Esther around the time it was written were quite familiar with Persian court customs and understood that the king was attended by guards who protected him and his honor. The king of Persia had a force of 10,000 men who the Greek historian Herodotus referred to as “the immortals” because as soon as one of the men were killed, wounded, or sick, he was immediately replaced by another man. The immortals were crack troops who fought for the king, and 1000 of them were handpicked to be the king’s bodyguards. It seems certain that some of them were in constant attendance to the king to protect him from attack and dishonor.
It was almost certainly the custom in Persia, like it was in Greece and Rome, that no condemned person had the right to look on one as exalted as the king, so the face of a condemned man was covered in the presence of the king. That certainly fits the circumstance occurring in Ahasuerus’ court. As soon as King Ahasuerus accused Haman of trying to rape Queen Esther in his very presence in his own house (even if what he said was hasty and somewhat hyperbolic), the guards took the cue and covered Haman’s face. Haman was doomed and was soon afterward impaled on the stake he had set up for Mordecai.