Judah ben Barzillai al-Barceloni, Perush Sefer Yesirah, p. 39

Jewish Mysticism
The prophets gaze upon the splendor of the Shekhinah and know that all the lights and images that appear to them are created. They see within these visions (mar’ot) as if they saw forms of a man made from fire and the great light. It appears to them in several images (dimyonot) according to the times and the situation in which Israel finds itself. It appeared to Moses from within a thorn-bush for Israel was amongst the thorns, in a time of great distress. It appeared to Moses and Israel upon the [Red] Sea as a youth engaged in warfare, and in the desert during the giving of the Torah it appeared “like the pavement of sapphire” (Exod. 24-10), i.e., in the image of an elder sitting down. Thus it also appeared to Daniel regarding the future redemption in the form of an elder sitting down… The prophets saw these images for they saw the fires and lights created from the splendor of the Shekhinah. From these lights and flames they saw their image which is the image of the anthropomorphic form of the splendor and the great fire… each and every prophet according to his capacity and the capacity of [the people of] Israel who were with him at the time, and in accordance with his period and that of Israel in which they were. All the images of the glory of our Creator [were not seen] with an actual vision (re’iyah mamash), as it is written, “and spoke parables through the prophets” (Hosea 12-11). But Moses our master… saw with an actual vision the great splendor which is the end of the created Shekhinah. He did not see any image (demut) of the glory of our Creator within the light, but rather the end of the form of the great light which our Creator created for His glory. Thus it says concerning him, “the glory of the Lord appeared” (Exod. 24-17). [With (Moses) I speak mouth to mouth] “in a vision and not through riddles” (Num. 12-8). If you say that it is also written concerning all the other prophets, “I make Myself known to him in a vision” (ibid., 6), this vision (mar’eh) involved knowledge (yedi‘ah) and not actual sight (mar’eh mamash). The Creator showed them created lights for their capacity for knowledge and vision was not as refined as that of Moses. Images appeared to them from amidst the lights, but not in an actual vision. Moses our master saw the end of the great light, i.e., an actual vision of the light and not through images, riddles or [figurative] visions.

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