Then Esther spoke to Hathach and instructed him to tell Mordecai,

Esther 4:5
Then Esther summoned Hathach, one of the king's eunuchs appointed to her, and she dispatched him to Mordecai to learn what was troubling him and why.

Esther 4:9
So Hathach went back and relayed Mordecai's response to Esther.

Esther 4:11
"All the royal officials and the people of the king's provinces know that one law applies to every man or woman who approaches the king in the inner court without being summoned--that he be put to death. Only if the king extends the gold scepter may that person live. But I have not been summoned to appear before the king for the past thirty days."

Again Esther spoke to Hatach, and gave him commandment to Mordecai;