We do not know how much time had passed between chapters 1 and 2, only that it could not have exceeded three years (see Esther 2:12, Esther 2:16). During this time, Ahasuerus’ anger had subsided. He regretted what he had decreed and longed for his former queen.
Behind Ahasuerus’ feelings of regret, we should perceive the hidden hand of God. The king’s heart is a stream of water in the hand of the Lord; he turns it wherever he will
(Proverbs 21:1). God steers everything for the good of his people, whether large public events or the private feelings of a king.
1 After these things, when the anger of King Ahasuerus had abated, he remembered Vashti and what she had done and what had been decreed against her.