Jewish Mysticism
The essence of intention is in the first three blessings [of the eighteen benedictions] for they are the praise of the Creator, blessed be He. When a person says, “Blessed are You, Lord,” he should not think about the glory seen by the prophets as it appears on the throne, but rather about the Lord who is God in the heavens above, without limit, whose place is hidden and concealed. For with respect to the visible glory (ha-kavod ha-nir’eh) the throne of glory is created to indicate to the prophets that there is a God. But with respect to Him there is no sitting and no image at all. It seems to me that one should also not pray to the hiding-place of his glory (hevyon ‘oz), but rather to the great light (ha-’or ha-gadol), concerning which it is written, “for no man shall see Me and live” (Exod. 33-20), and within it are comprised the glory and strength, “God is the Lord,” blessed be the name of the glory of His kingdom forever.

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