In one Ayah of Surat Ash-Shams, Allah Almighty says:

{He has succeeded who purifies it} (Ash-shams 91: 9)

What is “it” in the above Ayah?

It is the nafs (or the soul) that is mentioned in previous verses:

{And [by] the soul and He who proportioned it

And inspired it [with discernment of] its wickedness and its righteousness} (Ash-shams 91: 7-8)

So the one who engages in purifying and cleansing his soul has already attained success. The verse is not talking about having a pure soul; since that may be an impossible mission that would never happen. Everyone is vulnerable to his soul desires and shortcomings.  Rather, we are required to engage in the activity of constant self-purification. Obviously, you do not cleanse something that is already clean.

In this Video:

• Is it OK to deem yourself pure?
• Types of soul problems
• The Prophet’s supplication for his soul
• Your Role and Allah’s in self-purification