Tezkiyat al-nafs (purification of the nafs) emerges through tawba (repentance). When the nafs (the lower self) is purified by tawbat al-nasūḥ (sincere repentance), all its natural impurities are removed. The lack of sabr (patient endurance) stems from the impurities within the nafs, from its turning away (from what is right) due to these, and from its rebellion.
Tawbat al-nasūḥ softens the nafs and leads it away from its impure nature towards gentleness. For the nafs becomes clarified through muḥāsaba (self-examination) and murāqaba (spiritual vigilance), and its burning fire is extinguished by following caprice (hawā). Again, the nafs, through the state of itmi'nān (tranquility), attains the locus and station (maqām) of riḍā (contentment with God's decree), and becomes at peace in the face of the flow of destiny.
Tibb-i rūḥānī/tabīb-i rūḥānī (spiritual medicine/spiritual physician): This is the science of the perfections, afflictions, diseases, and treatments of the hearts (qulūb), as well as the preservation of their health and moderation, and protection from diseases.
The tabīb-i rūḥānī (spiritual physician) is the ʿārif shaykh (gnostic master) who knows tibb-i rūḥānī and is capable of irshād (spiritual guidance) and takmīl (spiritual completion). (Kāshānī, 65; Jāmiʿ, 88-89)