He may indeed have written pledge, but arguing that he must have, because being a craftsman in his writing he'd have felt compelled to put in the rhyme there - that just doesn't add up.

A craftsman poet could be quite capable of deciding to surprise the reader (or listener) by consciously refrainint from using the expected rhyme. In this instance, you hear "pl", you assume it'll be "pledge", and then it isn't after all.

So maybe he did it that way; and maybe he didn't, and the only way to settle it is to check with what the man wrote, and how he said it or sang it later on as well, because poets quite often change their own words, the same way people who write songs do.

I note that in the Ossian songbook (vol 3 Songs and Ballads popular in Irekand) it has "play", and that might be a factor in explaining why "play" seems to be more common when peopel sing it. But of course John Loesberg editing that must have got it from somewhere.

Isn't there anyone out there with Kavanagh's collected poems on their shelf?