'Command' in the Bible

"According to [the] law, what is to be done with Queen Vashti, because she has not done the command of King Ahasuerus {conveyed by} the eunuchs?

And the king's servants who [were] at the gate of the king said to Mordecai, "Why [are] you transgressing the command of the king?"

And the command of Esther established these practices of Purim, and [it was] written on the scroll.