Eleazar of Worms, MS British Museum 737, fol. 223a

Jewish Mysticism
It is customary for God to clothe the thoughts of His decrees, to show [them] to the prophets so that they will know that God has set His decrees. The prophet knows His thoughts according to the vision that he sees. At times this vision is called an angel.

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