What is the meaning of this Divya Prabandham verse?

Question

viShNuChitta in his Periyazhwar Thirumozhi 4.7.10 (overall pasuram #400) says:

மூன்றெழுத்ததனை மூன்றெழுத்ததனால் மூன்றெழுத்தாக்கி மூன்றெழுத்தை ஏன்றுகொண்டிருப்பார்க்கு இரக்கம் நன்குடைய எம்புருடோத்தமனிருக்கை மூன்றடி நிமிர்த்து மூன்றினில் தோன்றி மூன்றினில் மூன்றுருவானான்

mU^nR^ezhuttada^nai mU^nR^ezhuttada^nAl mU^nR^ezhuttAkki mU^nR^ezhuttai e^nRuk^oNDiruppArkku irakkam^ na^nguDaiya ^empuruDottamanirukkai
mU^nRaDi nimirttu mU^nRi^nil to^nRi mU^nRi^nil mU^nRuruvA^nA^n

The three syllables A-U-M, by three-syllable Nirukta, become the three, Akara-Ukara-Makara. Contemplating the three syllables OM expanded to three words with Namo-Narayanaya shows the three aspects of the Atman in three relationships with the Supreme manifested in three forms.

I was very confused by the lists of three in this verse, and I don't know Tamil. What are the "three aspects", "three relationships" and "three forms" referenced in this verse?

Answer 1

In this https://ramanuja.org/sri/BhaktiListArchives/Article?p=rest2003%2F0006.html website, the meaning of above Divya Prabandham verse is told

Three aspects of Supreme Lordship of Narayanan are - Seshithvam, Saranyathvam, Prapyathvamkaan.

Three relationships are

1. Ananya Seshathvam - not being a servant to anyone else

2. Ananya Saranathvam - There is no refuge other than Him

3. Ananya Bhogyathvam - the only bliss and enjoyment is in serving lotus feet of Bhagavan

The 3 Forms which Lord took in Trivikrama avatar : Asked for three measures of his feet nimirtthu- [with one step] took huge form moonrinil- Bhumi (earth), Anthariksham (space) and Swargam (heaven)