I was intrigued, so I read the three versions of The False Bride in the DT. The third one of them has this

The ladies and gentlemen asked o' me
How many black berries grow roon the salt sea
I gade aen back with a tear in my e'e
How many ships sail in the forest.

While this verse has its own internal logic, it doesn't seem to have anything to do with the story. Apparently the verse was just too much fun not to sing.