Continued from the biography of R. Zalman Duchman:
At the evening seuda of Shemini Atzeres 5729 (1968), R. Zalman began by telling the Rebbe that he had recited kiddush upon mashkeh (liquor). The Rebbe replied, “Very well! Today is Shemini Atzeres. ” The Rebbe then added, “You are older than forty, and that should be made clear, since otherwise everyone will go ahead and recite kiddush upon mashkeh.”
Later during the meal, R. Zalman asked the Rebbe to say something about the Frierdiker Rebbe, since on Shemini Atzeres he is the “ ushpizin” (holy guest). The Rebbe replied, “Here [in the Frierdiker Rebbe’s home] he is not a guest, but the baal habayis!”