Wayfarer wrote: "'gatherers of blah' is a reference to itinerent storytellers & songsters, that's all."

Since another verse has "Wi' ma bag o' blaw upon ma back", I believe it's "gatherers o' blaw [blow]", not blah, which according to Màiri Robinson's "Concise Scots Dictionary" is tinkers' cant for oatmeal. Which fits to another, slightly Anglicised version of the same song: "Wi a bag o' meal upon my back".

The song at least came through, if not from, tinker Jimmie MacBeath. But of course it's been folk-processed forever, so it's anyone's guess what stanzas are his.