amalanAthipirAn adiyArkku ennai Atpaduththa
vimalan viNNavarkOn viraiyArpozhil vEnkadavan
nimalan ninmalan neethivAnavan neeNmathiLarankaththammAn thiruk
kamalapAthamvanthu enkaNNinuLLana okkinRathE

Meaning:
Devoid of anything impure, responsible for all creations, helping me, making me a slave to His bhakthAs, of brilliant light, the Lord of nithyasooris, venkatEsa of the scented forests, one who helps without expecting anything in return, ruling paramapatham where justice always exists, residing in arangam which is made of lofty walls, His lotus feet on their own come and stay inside my eyes.

Essence:
periya perumAL's lotus feet have taken over thiruppANazhvAr completely. Water rains from the sky, then flows as kavEri and is useful to everyone through her feet (the streams); periya perumAL rains into thiruvEngadam from paramapatham, then flows south and dams at SriRangam, and thiruppANazhvAr immerses in His feet there.

Comparison to nammAzhvAr's muthaR pAsuram:

amalan (uyarvaRavuyarnalamudaiyavan)
Athi (yavan)
pirAn (mayarvaRa mathinalamaruLinan)
viNNavarkOn (ayarvaRumararkaLathipathi)
thirukkamalapAtham (thuyaraRu sudaradi)

nammAzhvAr said "thozhuthezhu" of His feet. For thiruppANazhvAr, they (His feet) came on their own ("vanthu") and stayed in him (his eyes).

amalan - Not only denotes that He is devoid of anything impure, but also that He makes all who are attached to Him devoid of the impure.

pirAn - Just as He created the worlds that were destroyed, He created the swaroopams that all beings destroyed themselves. Thus, AzhvAr says He helped in the past. But, He is also going to help in the future - AzhvAr, because of his being born had dOshams, and stayed away from Him; yet, He is going to come ("vanthu") and cleanse him ("enkaN pAsam vaiththa paramsudarsOthi").

adiyArkku Atpaduththa - If we are His devotees, there is a chance that we might slip out of that; but if we are a devotee of His devotees, then we would never slip out of that. Vibeeshana got to relate to His devotees first, before he met perumAL. thiruppANazhvAr met lOkasAranga rishi first before he saw periya perumAL. Thus, bhAgavatha sambantham is stressed here.

vEngadavan: Why did thiruppANazhvAr speak of vEngadavan when he opened his eyes to see periya perumAL? Our poorvAzhAryAs have said that when one begins to sing about someone, the first thing to do is to sing about his origins. Just as perumAL who descended on gOkulam (AyppAdi) from paramapatham stopped at mathurA, so did He stop at thirumalai when descending from srIvaikuntam to srIrangam.

viNNavarkOn: There is no need for us to wonder, when are we going to be with everyone in the other world? He is without limits even to them (their Lord).

ammAn: Perhaps after hearing about the lofty walls here, did our Kaliyan build them? Only after these songs, did the houses, and the gOpurams grow in Arangam. Once this place became equivalent to that place, emperumAn took rest here.

vanthu: "iruppEn enRu en nenju niRayap pukunthAn"

enkaNNinuLLana: What is always seen by the nithyasooris, suddenly became visible to AzhvAr. Prior to that, he had not looked at Him. His eyes were closed to Him. EmperumAn cut through the closed eyes and settled in. Or that AzhvAr thought, he should not see Him with his mortal eyes and closed them, but emperumAn went inside his eyes and started glowing there.

From vEdAntha dEsikar's munivAhana bhOgam:

amalan: mOkshaparathathvam

Athi: kAraNathvam (cause for all creations)

pirAn: sarvopakArakan (guiding one and all)

adiyAr: By this word, defines jeevAthmAs and establishes that they are different from emperumAn.

Atpaduththa: paramOpakAran - is there a greater help that He can do, than that of making one a devotee of His devotees.

vimalan: nithya nirthOshan (eternally pure)

viNNavarkOn: pararoopam (unattainable even to the other worldly)

virayArpozhil vEngadavan: Yet reachable to everyone in this world.

vAn: paramapatham

vanthu: Even though AzhvAr was running away from emperumAn, He came after AzhvAr.

enkaNNinuLLa okkinRathE: AzhvAr is unable to tear his eyes away from His lotus feet. His feet are unreachable to Brahma, the dEvAs, rishis, and yet came and stayed inside a mortal's eyes.