Ma‘arekhet ha-’Elohut, ch. 10, 144a

Jewish Mysticism
Know that a person’s physical form is made in the [likeness of the] supernal image (demut ‘elyon), and the supernal image is the [sefirotic] edifice… Now that you know the human form (surat ha-’adam), if you have received through oral transmission, you can comprehend the truth of the prophetic vision seen by the prophets. The rabbis, blessed be their memory, called this vision the measure of the stature (Shi‘ur Qomah).… Concerning it is said in Scripture, “Let us make man in our image and in our likeness” (Gen. 1-26), and regarding the vision it is said, “and through the prophets I was imaged” (Hosea 12-11). R. Isaac [ben Todros] said that [this is alluded to] by the sign, the [word] temunah [image] numerically equals [the expression] parsuf ’adam [human countenace]. I have also found this in the words of R. Eleazar of Worms.

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