See “H|iddushei Halakhot ve-Aggadot,” by Samuel Eliezar Edels (“Maharsha”), in Tractate Megillah (New York: Pardes, 1944), appendix, p. 10, col. 1. See also Adin Steinsaltz’s marginalia to Megillah 25b (p. 109) in his edition of Talmud Bavli (Jerusalem: Israel Institute for Talmudic Publications, 1983). I am indebted to my father, Rabbi Michael Minkoff, for these references.