Sutra:
93. azhikkaikku hEthu keezhE solliRRu; mElum sollum.

Meaning:
What is the reason for the soul to perform naicchiyam and destroy His joy when He mixes with the soul? That cause is the same that is explained in the prAnavam, which is that the nature of the soul is sEshatvam. This was shown before and will also be shown in the open fourth case that follows.

Sri PBA Swami's Sarartha Deepikai:
Previously it was told that the soul should not destroy His joy when He mixes with and enjoys it. As said in "prasaktasyaiva hi pratishedha:", something should be prevented only if there is a chance for it to happen; so, is there a chance for the soul to do that?

It is possible, because the reason for the removal of His joy is the same sEshatvam that was said in the praNavam as the nature of the soul. This will also be shown in the explicit fourth case (Aya) that follows.