Thanks for that information, Bruce. There are a couple of other Gaelic songs with a similar line, including classical verses in Scottish Gaelic by Sìleas na Ceapaich under the title 'Tha mi am chadal, na dùisgibh mi' (I am asleep; don't waken me). I understand that song has been recorded by Anne Lorne Gilles on Lismor records but I haven't managed to get the words of that song. I'm reminded of the discussion of "calen o custure me" /calleno..., Is cailín ó chois tSuire mé - the same line is repeated in different songs.