rav ada verav shalman tarvai-hu ........ eich yavo-ou lit-ot in nemar ki malea haarets dea et hashem camayim layam mechassim.?
albert battat, sao paulo brazil
(Editor's Translation: Concerning the opinion of Rav Ada and Rav Shalman, who are concerned that when the Beis ha'Mikdash is rebuilt, people will make a mistake and think that the Halachah is the same as it was the previous year, how could it be that there is a fear that the people will make a mistake? Doesn't the verse state that in the future, "The land will be full of knowledge of Hash-m like the waters cover the sea" (Yeshayah 11:9)?)
Atah shoel eich chosheshim l'taus b'halachah "k'sh'yibaneh beis ha'mikdash,v'male'a ha'arets deah, k'mo sh'kasuv b'Sefer Yeshayah.
Amnam, ka'nireh sh'binyan beis ha'mikdash yihiyeh lifnei "male'a ha'arets deah," sh'ha'beis ha'mikdash yibaneh miyad b'bo ha'geulah u'b'bias ha'Mashiach, k'sh'adayin lo hispik melech ha'mashiach l'lamed kol ha'am deah.
(Translation: You are asking how can there be a concern that people will err in the Halachah, when Eliyahu will have already come, as well as Mashiach, and "the land will be full of knowledge."
It seems that the answer is that the rebuilding of the Beis ha'Mikdash will happen before "the land will be full of knowledge," for the Beis ha'Mikdash will be rebuilt right away, while it will take some time for Mashiach to teach the entire nation the knowledge of Hash-m.)