Moses went into the cloud and climbed to the top of the mountain. Rabbi Shimon asked: Wasn’t the Holy Blessed One upon Mount Sinai, and [in this regard] it is written, “The glory of G-d appeared like a consuming fire on the mountain top” (Shemot 24:17)? So how was Moses able to ascend the mountain?
Similarly with Eliyahu about whom it is written, “Eliyahu ascended to Heaven in a whirlwind” (Kings II 2:11). How was Eliyahu able to ascend to the heavens? Is it not so that Heaven cannot tolerate any physical object from this world, even one as tiny as a mustard seed?
However [the explanation is that] he entered that whirlwind and clothed himself in it, and within that whirlwind he was able to ascend on high.
This mystical secret is explained in the Book of Adam, where it discusses the [unfolding] chronicle of the universe: In the future a certain spirit [Ruach] will descend to the world and will be clothed in a body upon earth. “Eliyahu ” will be his name. In that very body he will ascend. But he will divest himself of that body, which will remain in the whirlwind, and another body – of light – will be prepared for him, enabling him to be among the angels. When he wishes to descend to this world he will again clothe himself in the body that remains in the whirlwind. It will be in this [latter] body that he will be revealed below, whereas he is revealed above in the other body [the body of light].