Sutra:
266. ennudaiya nigrahapalamAy vandhavai nAn iranginAl kidakkumOvenkai.
267. anAdhi kAlam pApangaLaik kaNdu nee patta pAttai avai thAm padumpadi paNNugiREn.

Sri PBA Swami's Sarartha Deepikai:
What is the meaning of saying that they will leave on their own?

The chetana who does these sins will forget them because he is ignorant. The Lord, who knows everything and who forgets nothing, is the one who gives out the fruits of these acts at the appropriate times. These come out of His act of handing out punishment. He is asking "If these come out of my nigraha rUpa, would they stay when I put on the opposite form of anugraha rUpa".

That is, the chetana was afraid of these for a long time. Now, He will make them fear the chetana and leave him.