Turning/repentance [tawba] is the mark of the road, the leader to the court, the key to the treasure, the intercessor of union, the head of every happiness, and the basis of freedom. First is regret in the heart, second apology with the tongue, and then cutting off from bad things and bad people.
4:17 It is for God to turn only toward those who do the ugly in ignorance and then soon turn. Those—God will turn toward them. And God is knowing, wise.
It has come in the report that when someone repents but does not put aside bad friends, he is not a repenter. When someone repents but does not put aside food and drink, he is not a repenter. When someone repents but does not put aside his bedclothes and empty his eyes of sleep, he is not a repenter. When someone repents but does not expend the wealth left over after food, he is not a repenter.
The precondition of repentance is that you detach your heart from all existent things and turn it toward the Real. You discipline all the blood and flesh in your seven bodily members. Repentance is the precursor of the fire that comes from the bottom of hell so that today you will do to yourself with the water of your eyes what will be done to you tomorrow by the fire. Repentance is a message sent to you from the Presence: “O chevalier! How long will you make war? How long will you break the covenant? Come back, make peace!