Nekkhamma: Renunciation, the letting-go
The wicked is told to forsake his way, to set down the road he has been walking. This is the plain act of releasing a path once it is seen to lead wrong, walking away from it empty-handed. Like a man dropping a rope that has burned his hands, he simply lets the old way go.
Cittavisuddhi: Purification of the mind
The unrighteous man is asked to forsake his very thoughts, past his deeds down to what feeds them. The cleaning reaches the source, the thinking under the wrongdoing. It is scrubbing the well, not just wiping the cup.
Paṭinissagga: Relinquishment, the turning back
To return unto the LORD is to reverse direction entirely, to turn the whole self around toward what is good. This is the about-face at the heart of change, the road walked back the way it came. The traveler who was going out now sets his face toward home.
Khama: Forbearance, forgiveness
The turning is met with abundant pardon, mercy poured out past measure. However far the way has gone, the debt is released in full when the man comes back. The one who forsook his path finds not a reckoning waiting but open hands.