whose devotion —

the ocean of devotion that is ṣrī rāmāyaṇam —

words combined by devotion —

which does not have (their level of) devotion (towards emperumānār) —

this decad-s —

emperumān who takes all the efforts for the chĕthana to develop devotion towards him —

the thathvam of devotion (bhakthi) (prāpya ruchi – taste/interest for getting the destiny), —

 due to bhagavath bhakthi —

of the desire (which is the cause for such poem) —

based on devotion. —