Zohar Hadash 28b

Jewish Mysticism
R. Judah taught- Whoever is occupied with [the study of] Torah as much as is required, his soul is elevated above when he is asleep, and he is taught from the depths of Torah … R. Isaac taught- Whoever is occupied with Torah for its own sake, when he is asleep at night his soul rises and he is shown those matters that will be in the world in the future.

Translated by Elliot Wolfson in “Forms of Visionary Ascent and Ecstatic Experience,” in Gershom Scholem’s Major Trends in Jewish Mysticism 50 Years After 209-235. Edited by J. Dan and P. Schafer, Tubingen- J. C. B. Mohr, 1993.