Nafs is an Arabic word (cognate of the Hebrew word "Nefesh" נפש ) which occurs in the Qur'an and means self, psyche, ego or soul. In its unrefined state, "the ego (nafs) is the lowest dimension of man's inward existence, his animal and satanic nature." Nafs is an important concept in the Islamic tradition, especially within Sufism and the discipline of gnosis (Irfan) in Shia Islam. Nafs means inner self - the evil side of your soul. It varies for every person. Tradition states it is a little black spot on the area where the person's heart is and it is mentioned in the hadith that the prophet Muhammad had this spot removed.