From: Rabbi Moshe Sofer
To: Rabbi Yehuda Assad
Rabbi Yehuda Assad asks why poskim ignore the Meiri's ruling that Hallel may substitute for Megillah reading on Purim. The Chasam Sofer explains the Meiri's Talmudic reasoning but rejects his position, ruling Hallel is at most a last resort.
Source: Shu"t Chasam Sofer OC §192