Perhaps it is mentioned and we never noticed it?
The Maharal of Prague explains (in Tifferes Yisroel, in relation to why we
are required to read the Torah Portion three times each week - text 2X,
targum 1X) that Torah exists on three levels: 1)A surface level that is
apparent to everyone who studies it 2)A concealed level, containing the
deeper meaning of the mitzvos, available to those scholars with the ability
and training to understand and recognize it and 3)A totally hidden level
that discusses the WORLD TO COME and is beyond the cognition of any human
being - just as the World To Come is necessarily beyond our comprehension.
This is consistent with the idea that the Prophets only prophesied
regarding the period up to the time of Moshiach - but not beyond. Only G-d
has seen what this period will be like.
There are allusions to the World to Come: promises of "length of days" and
"life", interpreted by the Rabbis to be references to the World to Come,
but lacking any description of what this world would be like. But, the
Maharal is saying that the Torah is replete with descriptions that are at
this point beyond our comprehension.
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