John Gill Commentary Esther 4:10

"Then Esther spake unto Hathach, and gave him a message unto Mordecai [saying]:" — Esther 4:10 (ASV)

Again Esther spoke unto Hatach
For there was no other way of corresponding and conversing but by an eunuch; the wives of kings being altogether under their watch and care:

and gave him commandment unto Mordecai ;
to go unto him, and what he should say to him from her, which is as follows.