Tazkiyah literally means purifying something. There are many commandments of Shariah which pertain to a person’s body, as in they are carried out physically. Some of them are DOs (اوامر) for example, pray Salah, observe fasting, give Zakat, perform Hajj, etc., and some of them are DON’T’s (نواہی), for example, do not tell a lie, do not do Gheebat(backbiting), do not drink alcohol, do not steal, do not commit robbery, etc.

In exactly the same way, there are many commandments of Shariah which pertain to a person’s mind, or inner self. Some of these are DOs called Awamir (اوامر). Developing these good moral values is Wajib (necessary) and a person’s Deendoesn’t become complete unless he develops these good moral values. For example, it is Wajib (necessary) to perform Shukr (being thankful to Allah Ta’ala for His blessings upon us), observing Sabr (patience, steadfastness) if something undesirable happens, observing Tawakkul (placing one’s complete trust in Allah Ta’ala), developing Tawazu (humility, believing others to be better than oneself), and developing Ikhlas (sincerity of intention, meaning whatever a person does, he does it solely with the intention of seeking Allah Ta’ala’s pleasure and approval). Developing Ikhlas is Wajib as no act of worship is acceptable without Ikhlas. All these good moral values such as Shukr, Sabr, Tawazu and Ikhlas are called Akhlaq-e-Fazilah (اخلاقِ فاضلہ) and trying to develop them is Wajib (necessary).

Similarly, there are some bad or undesirable moral values in our minds or inner-self which are Haraam (impermissible) and we must try to remove them from our minds. These are called Akhlaq-e-Razilah (اخلاقِ رذیلہ). If these traits are present in us, then a person has to try to suppress and attenuate them so that they do not lead a person to commit sinful acts. The examples of such undesirable mental traits are Takabbur (تکبّر) (grandiosity, believing oneself to be superior to other people), Hasad (حسد) (envy, being jealous of the good things others have and wishing or making efforts that they lose them), Riya (ریا) (doing acts of worship with the intention of pleasing people, rather than pleasing Allah Ta’ala), and impatience (بے صبری) (not accepting what Allah Ta’ala has decided for us and keep complaining about fate), etc. Having the habit of becoming unduly or excessively angry without just reason is also one of these bad moral values. These bad moral values are as Haraam (impermissible) as committing a robbery or telling a lie. 

In summary, there are some good or desirable moral values (Akhlaq-e-Fazilah) pertaining to our inner-self which it is incumbent upon us to develop, and there are some bad moral values (Akhlaq-e-Razilah) pertaining to our inner-self which we are required to attenuate and control. The role of a Sufi Shaykh is to inculcate and enhance the former, and attenuate and weaken the latter, in the minds of his spiritual pupils called Mureed (مرید).