pas’cAt tApa: is the suffering that one undergoes after doing something wrong. This ‘undoes’ the pApa or sin that a person has committed. That ‘undoing’ is called niSkRti. Paschattapam may be translated into english as repentance. This itself is cleansing.
prAya: cittam : (rejuvenating the consciousness?) is atonement or making amends. A repentant person makes amends as prescribed by the good and wise to be free from all kinds of sins.
Having made amends (atoned) as prescribed, that repentant person attains a good gati (path), without a doubt. This sugati can refer to the path after death too.
But the purity of citta (consciousness) that is attained by listening to the s’iva purANam cannot be attained by other means.
Because, it cleans up the citta like a polished mirror and śiva and ambika live in such a citta. And a highly purified self like that attains the pada (state) of s’iva and ambika.
This story was first told by s’iva and it holds the mind firmly to s’iva. It gives us dhyAna or attention to s’iva.
dhyAna gives us gnyAna or the highest knowledge. That gnyAna leads to kaivalyam. kaivalyam is the state of kEvala or ‘only’. It is the state where you realize that there is ‘only one’.