Something interesting I just noticed:
We have a book of poetry called Opened Ground
by Seamus Heaney, and the first poem in it is called Digging
Coincidence? Maybe. The poem is about Seamus' Dad diggin in the garden, so it doesn't fit in with the lyrics of the song, but maybe
Osten got the seed of inspiration from this, and it just grew in a different direction. Maybe.
Still interesting anyway