To
cleanse or purify the heart and the soul.
The following verse of the
Quran Illustrates this:
By
the sun and its brightness, by the moon as it follows
it, by the day as it shows its brightness, by the
night as it conceals it, by the heaven and its wondrous
make, by the earth and all its expanse, and
by the soul and He Who perfected it in proportion,
then He showed it what is wrong for it and
what is right for it - indeed he succeeds who purifies
it, and he fails who corrupts it."
[Ash-Shams 91:1-10]