According to
this, the poem is:
Seduction of the RingI tuo, i macil -
Astaldaron mauri
Nai corma macilya
A lelyat túrenna!Which translates as:
The strength, the weapon -
The needs of the valiant.
Be the ring your weapon
Go to victory.
It is worth remembering that it the whole poem is not heard in the song. The poem does occur in other places:
- in the standard TFOTR soundtrack you can hear it in Amon Hen (track 16) / this is also track 5, disc 3 of the extended soundtrack;
- The Forbidden Pool (track 13) in the standard TTT soundtrack;
- it may very well appear elsewhere but I can't think of any examples of it at the moment.