Another interpretation is that the heavens declare the glory of God, as the verse says in Psalms 19:2, "The heavens declare the glory of God; the skies proclaim the work of his hands." Rabbi Shmuel bar Abba said, "I am familiar with the heavenly realm just as I am familiar with the streets of Nehardea." Did Shmuel actually ascend to the heavens? No, rather through his study of Torah, he gained knowledge of what is in the heavens.
Rabbi Hoshaya said, "Just as there is a space between the lower waters and the sky, there is also a space between the upper waters and the sky." Rabbi Pinchas HaKohen bar Chama said, "The verse in Genesis 1:7 states, 'And God made the expanse and separated the waters that were below the expanse from the waters that were above the expanse.' This only refers to the waters above the expanse, which are dependent on the air.
The upper waters produce rain, as it says in Psalm 104:13, 'He waters the mountains from his chambers; the earth is satisfied by the fruit of your work.' Did Rabbi Hoshaya actually ascend to the heavens? No, rather through his study of Torah, he gained knowledge of what is in the sky.