"Run for Your Life"

I listened to Rubber Soul a couple days ago, after which I realized that the line "Let this be a sermon; I mean ev'rything I said" in "Run for Your Life" could be understood two ways.  I'd always taken "I mean ev'rything I said" as the narrator's explanation of what he means by "this."  "Let ev'rything I said be a sermon."  It could also be understood as an unrelated clause though, in which the narrator is simply affirming his statement.