Matzpun is the Hebrew for conscience. The word first appears in the Book of Obadiah(1:6), who predicts the downfall of Edom. "How thoroughly rifled is Esau, how ransacked [matzpunav]." Obadiah uses matzpun to refer to hidden treasure. The part of the Passover Seder in which we eat the hidden afikoman is called tzafun, meaning hidden.
Tzafon means "north" and derives from the Ugaritic for the "hidden or dark region", hence its additional Hebrew meaning of concealed.
In Arabic, damara literally means hidden and, metaphorically, conscience. When translating Rabbi Yeudah Halevi's Kuzari from the Arabic to the Hebrew, the renowned 12th-century Provencal translator, Rabbi Yehuda ibn Tibbon used matzpun to refer to hidden thoughts and ethics: "Your reward shall be manifold for the purity of your heart and your matzpun" (Kuzari 5:25). One unidentified medieval quotation speaks of the tongue as the "heart's quill and envoy of the matzpun".