Since it was customary for the king to consult experts in matters of law and justice, he spoke with the wise men who understood the times1
References for Esther 1:13
and were closest to the king--Carshena, Shethar, Admatha, Tarshish, Meres, Marsena and Memucan, the seven nobles2 of Persia and Media who had special access to the king and were highest in the kingdom.
References for Esther 1:14
"According to law, what must be done to Queen Vashti?" he asked. "She has not obeyed the command of King Xerxes that the eunuchs have taken to her."
Then Memucan replied in the presence of the king and the nobles, "Queen Vashti has done wrong, not only against the king but also against all the nobles and the peoples of all the provinces of King Xerxes.