Imprison it, and in every moment of heedlessness, complain of your incapacity to Allah. That (nafs), as expressed in the verse, "You have not yet gained mastery over it, but Allah has encompassed it" (al-Baqara 2:5), is what is meant here. If it (the nafs) tries to direct you toward any of its claims, you must remember the blessing of your Lord.
(See also: mujāhada; sharia-ḥaqīqa)