Eleazar of Worms, Sode Razayya, p. 11.

Jewish Mysticism
The angel [appears] in many images (demuyot), and this is [the import of the verse] “The one who looked like a man touched my lips, and I opened my mouth and spoke, saying to him who stood before me, “My lord, because of the vision, I have been seized with pangs and cannot summon strength” (Dan. 10-16). It does not say in the image of a man (ki-demut ’adam) [i.e., in the singular], but rather in the image of men (ki-demut bene ’adam) [i.e., in the plural], for the angel [can appear in] many images. The angel appointed over a man looks like that very man.

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