Esther 2:21

2:21 In those days while Mordecai was sitting at the king’s gate, Bigthan and Teresh, two of the king’s eunuchs who protected the entrance, became angry and plotted to assassinate King Ahasuerus.

Esther 6:2

6:2 it was found written that Mordecai had disclosed that Bigthana and Teresh, two of the king’s eunuchs who guarded the entrance, had plotted to assassinate King Ahasuerus.