Esther 4:15, 16a-d, 17 (NKJV)

Then Esther told them to reply to Mordecai: 'Go, gather all the Jews who are present in Shushan, and fast for me; neither eat nor drink for three days, night or day. My maids and I will fast likewise. And so I will go to the King, which is against the law...' So Mordecai went his way and did according to all that Esther commanded him.