Matthew Poole and continuators on Esther 9:31

31 To confirm these days of Purim in their times appointed, according as Mordecai the Jew, and Esther the queen, had enjoined them, and as they had decreed for themselves and for their seed, the matters of the fasting and of their cry .

For or about those great and overwhelming calamities which were decreed to all the Jews, and for the removing of which not only Esther, and the Jews in Shushan, but all other Jews in all places, as soon as they heard those dismal tidings did doubtless according to the precepts of Scripture, and the constant practice of their godly Predecessors in all Ages, fly to that last and only Refuge of seeking to God by Fasting, and earnest Prayers and strong Cries unto God; which God was pleased graciously to hear, and in answer thereunto to give them this amazing Deliverance. And this was that which they were now to remember, to wit, the greatness of their danger and of their rescue from it. And accordingly the Jews use to observe the first of these days with Fasting, and crying, and other expressions of vehement grief and fear, and the latter with Feasting, and Thanksgiving, and all demonstrations of Joy and Triumph.

Marginal references: Heb. for their souls.