To confirm these days of Purim in their times appointed,.... The fourteenth and fifteenth of Adar:according as Mordecai the Jew and Esther the queen had enjoined them; in the letters written and signed by them both:and as they had decreed for themselves, and for their seed; see Es 9:27,the matters of their fastings and their cry; in commemoration of their deliverance from those distresses and calamities which occasioned fastings and prayers during the time of them; and to this sense is the former Targum; though it is certain the Jews observe the thirteenth day, the day before the two days, as a fast, and which they call the fast of Esther , and have prayers on the festival days peculiar to them; but the sense Aben Ezra gives seems best, that as the Jews had decreed to keep the fasts, mentioned in Zec 7:5, so they now decreed to rejoice in the days of Purim.
Lebush & Schulchan, ut supra, (par. 1.) c. 686. sect.