Judah ben Barzillai al-Barceloni, Perush Sefer Yesirah, p. 67

Jewish Mysticism
This vision that Zechariah saw was a visual image (dimyon mar’eh) and not an actual thing (mamash), but it was rather as if the Holy One, blessed be He, gave him power in his eyes and heart to see the measurement of Wisdom, which is the Torah… The Holy One, blessed be He, gave him power to see with his eyes as if he saw with a vision of his eyes and imagined in his heart a scroll 3,200 times greater than the whole world. Thus no human possesses knowledge to conjecture if the Holy One, blessed He, created the place of the Torah above the seven heavens in this measurement. [The Torah scroll] is an entity that is not [materially] real (beriyyah she-’eino mamash) as is the world, but is rather a form with measurements and dimensions in the manner that [the glory] was shown to Isaiah… The created world is an actually existing entity and thus [can be seen] with a vision of the eye (re’iyat ha-‘ayin), whereas the vision of the Torah is not [attained] by means of a physical vision but through a vision of the heart (re’iyat ha-lev).

Translated by Elliot Wolfson in Through a Speculum that Shines- Vision and Imagination in Medieval Jewish Mysticism, Princeton- Princeton University Press, 1994.