Further to some points made above:   first, I've seen a short clip on Television of PK singing (in a Traditional manner) his own "DofD" to the Fainne Gael an Lae air, which together with the repetition of that phrase does tend to confirm that these were "words for music perhaps". Secondly, Tom Bliss's contribution above is most useful with regard to the internal rhyming; it's worth bearing in mind that assonance and assonantal patterning is very much a feature of Irish (i.e. Irish language) song. However, I can't agree that the melody is ponderous, tho' some might perform it or regard it in that way. Another feature of traditional singing - at least, when it's unaccompanied (as it ought to be - but that's another matter...) - is the freedom which singers will allow themselves with tempo and time and rhythm, the speed of the music being guided by the sentiment being presented. Take it a little further, even; need each verse even have exactly the same melody, note for note? I'll not go into detail, but on two occasions I think it acceptable to introduce a very slight variation to the musical line; again, a feature of traditional music (especially instrumental, of course) Finally, the difficulties of the beginning of the third verse are primarily, in my view, to do with the length of the phrasing which ought ideally to be given without breaking for breath; if one takes the liberties I've suggested with regard to tempo &c., then the sense can be made come through with the melody not unduly compromised. All depends on skilful breathing, breath-control and indeed lung-capacity; 'tis a pity John McCormack was of the earlier generation, because it would take someone like him - or Jussi Bjorling - to deal confidently with this aspect.