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 2:23

2:23 The king then had the matter investigated and, finding it to be so, had the two conspirators hanged on a gallows. It was then recorded in the daily chronicles in the king’s presence.

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.