R av Moshe did not appreciate being asked to predict the future. He would respond to nudniks with comments like “I don’t know what will happen tomorrow! How do you expect me to know when Mashiach is coming?”
If we don’t know when Mashiach is coming can we at least know what the world will be like when he arrives? After all Rambam devotes the last two chapters of his Mishneh Torah to a vivid description of that era.
To answer this question Rav Moshe shared a critical distinction he heard from the Brisker Rav.
In Rambam’s portrayal of the Messianic Era he inserts the following quotation. “Lo yeida adam eich sheyiheyu ad sheyiheyu — A person will not know how it will be until it is” (Hilchos Melachim 12:2). We won’t know how it will happen until it actually happens.
