Which is the most ancient commentary on song of Solomon, that attempts to explain its narrative

There are lots of ancient commentaries on the book, most notably Origen's . However these seem to be chiefly interested in spiritual content (questions like what horses bridles/lilies may represent), I am unaware of any that concern themselves with the story of the book before the 12th century. By story of the book I mean, things like: who is saying each line, what the scene they are in is, how the narrative has developed from previous scenes. It seems unlikely to me that Christians (and Jews) would read the book for well over a millennia before anyone thought to ask questions about the narrative of the book.