Ba'al Shem Tov, Esther 7/בעל שם טוב על התורה·מגלת אסתר ז׳

1…and these days of Purim should not pass away from among the Jews, nor the memory of them perish from their seed. (ibid. 9:28)They will never pass away, for in each and every generation, they are recalled and re-experienced, as my grandfather (the Baal Shem Tov) said.Degel Machane Ephraim, derash l’Purim