This is an example of an ancient riddle song. These is usually a contest of competing riddles but in this case the answering riddles are omitted. It is very similar to two ballads in the Child collection"The Elfin Knight" (Child 2) and "Riddles Wisely Expounded" (Child 1) (also known as "The Devil's Nine Questions"). The recurring "parsley, sage, rosemary and thyme" is a medieval herbal incantation to sweeten and refresh the relationship with the lover. This is not quite the tune used by Simon and Garfunkel.