sattAsthiti prayatnapramukhairupAttam
	svArtham sadaiva bhavatA svayameva vishvam |
dIpaprakAsha tadiha tvadavAptaye tvAm
	avyAjasiddhamanapAyamupAyamAhu: ||

Meaning:

dIpa prakAsha 			- O Deepa Prakasha!
sattA 				- The creation, 
sthiti 				- sustenance, 
prayatna 			- actions 
pramukhai: 			- and such things 
vishvam 			- of (all the beings in) this world 
bhavatA upAttam 		- are done by You, 
svayam eva 			- by Yourself alone, 
sadA eva 			- forever, 
svArtham 			- for Your purpose only.
tat 				- Therefore, 
Ahu: 				- (great people) say 
iha 				- in this world, 
tvat avAptaye 			- that to attain You 
tvAm 				- You Yourself are the
siddham 			- already present 
avyAja 				- causeless 
anapAyam 			- and indestructible 
upAyam 				- means.

Vyakhyana Saram:
In the prior shlokas, Swami Desikan showed the greatness of sharaNAgati and to whom it must be done. This may lead some to believe that the act of sharaNAgati itself is the means to attaining Him. In this shloka, he is clearing that misconception and shows that it is He who is the means to attaining Him and nothing else.

Swami Pillai Lokacharyar says "pullaik kAtti pullai iduvAraip pOle" - that is, a cowherd will show grass to attract a cow; once the cow comes near, he will not give it something else; he will feed the cow the same grass that he showed it. Similarly, the Lord shows His feet to the chetana and asks him to surrender at that feet ("mAm ekam sharaNam vraja"). When he does, it is the same feet that He gives to the chetana. Therefore, it is His divine feet that are both the upAyam and the upeyam. Nothing else is upAyam. Vedanta Desikan is showing that our sampradhAyam is siddhOpAya sampradhAyam and not sAdhyOpAya sampradhAyam.

All the acts of the chetana are due to Him and are for His purpose only. The act of sharaNAgati is also included in this and cannot be taken as a separate thing. Thus, He alone is the means.

Just as Brahmastra does not accept anything else working with it (in Ramayana, when the rakshasas tied Hanuman with ordinary ropes after he had been bound by the Brahmastra, the Brahmastra released him), so too His being the means does not tolerate the idea that anything else including the act of sharaNAgati could be the means.

His being the means is also causeless - nirhetuka krupa. He does not require anything from the chetana to shower His mercy on him. All that the chetana has to do is to resist receiving this mercy and accept it with open hands.