Esther 2:21 (ESV)

21 In those days, as Mordecai was sitting at the king’s gate, Bigthan and Teresh, two of the king’s eunuchs, who guarded the threshold, became angry and sought to lay hands on King Ahasuerus.

However rich and secure a king might have been, if his own bodyguard conspired to kill him, he was in grave danger! Yet in God’s providence, this conspiracy took place as Mordecai was sitting at the king’s gate.