“The soul, which in its real condition was of the form of Siva, was confined and conditioned by its original anava mala. When this mala ceased to obstruct the soul, the soul resumed its original form of Siva.
A : The clarification requested requires elaborate explanations. However I would put it in succinct as this. The word Aanavam is a pure sanskrit word meaning the one which made the Aanma(soul) into a small Anu(atom). The word Aanma in turn means that expanding into omnipresence. This word namely Aanavam is taken in the above meaning by Thirumoolar and referred to in many of the verses in Thirumanthiram.
True to the meaning of the above, Thirumoolar in his seventh thantra under the caption Purudan and Jeevan written poems as below which will be of nearest context to your requirement. May be it is not given in one poem as a whole but scattered in two/three poems in juxtaposition.
Purudan:
Anuvul avanum avanul anuvum
Kanuvara nindra kalappathu unaraar
Inayili eesan avanengum thaanaagi
Thanivara nindraan saraasaram thaanay (TM 2010)
Padar konda aalathin viththathu pola
Sudar konda anuvinai thoovazhi seyya
Idar konda paasa irulara votti
Nadar konda nalvazhi naadalu maamay (TM 2009)
Jeevan:
Mayviya seevan vadivathu sollidil
Kovin mayirondru noorudan koorittu
Mayviya koorathu aayiram aanaal
Aaviyin kooru nooraayirathu ondray (TM 2011)
In TM 2011, Thirumoolar gives an account of how much the size of a soul is, which none other than him ventured to say. He says, the size of a soul is approximately equivalent to one in lakh of a hair shred of tail of a cow. Note that the said hair should be split along the grain i.e. it should be split vertically and not horizontally. This is tantamount to saying that the size of the soul is far more small that it is as invisible as an atom.
It may also be noted that he has referred in this context to hair shred of a cow, which will not be dark but in contrast gray, meaning the soul is a light but dimmed.
Thirumoolar, therefore, taking this into consideration of the above refers ‘purudan’ as anu in TM 2010. The meaning of the verse is self-explanatory.
In TM 2009, Thirumoolar says the very same idea in other words that the purudan is as small as a seed of Banyan tree. It is capable of catching light and hence the soul in an atom form, on lighting by external means, here by splendorous light of the Almighty, attains a stage of purity, pure from ignorance (Aanavam). The soul having been tangled in the clutches of Aanvam (here it is referred as Irul) is extricated out of it and comes into the right path where it can reach the Almighty in dancing form (here it is referred as natar).
These three poems, very closely related to each other, considered and analyzed adjacently will serve the purpose of your requirement.
I have also another point to tell you. People normally call uyir as soul. But it is not right. The word soul in English means mind and activities associated with it. In this meaning it refers to purudan mentioned above. The right word for uyir in English will be self.