Esther 4:15 (KJV)

Again Esther spake unto Hatach, and gave him commandment unto Mordecai;

All the king's servants, and the people of the king's provinces, do know, that whosoever, whether man or women, shall come unto the king into the inner court, who is not called, there is one law of his to put him to death, except such to whom the king shall hold out the golden sceptre, that he may live: but I have not been called to come in unto the king these thirty days.

And they told to Mordecai Esther's words.

Then Mordecai commanded to answer Esther, Think not with thyself that thou shalt escape in the king's house, more than all the Jews.

For if thou altogether holdest thy peace at this time, then shall there enlargement and deliverance arise to the Jews from another place; but thou and thy father's house shall be destroyed: and who knoweth whether thou art come to the kingdom for such a time as this?

Go, gather together all the Jews that are present in Shushan, and fast ye for me, and neither eat nor drink three days, night or day: I also and my maidens will fast likewise; and so will I go in unto the king, which is not according to the law: and if I perish, I perish.

So Mordecai went his way, and did according to all that Esther had commanded him.