Sefer ha-Temunah (Lemberg, 1892), 25a

Jewish Mysticism
Thus everything is found in the tradition of the kabbalists who comprehend everything by means of the prophets from the verses that indicate the matter in verses that are known to those who comprehend. These [scriptural verses] are called ‘chapter headings’ for they are the limbs of the body, and the sefirot are in a human image, for man is a microcosmos, as it says, ‘Let us make man in our image and in our likeness’ (Gen. 1-26).

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