If Sydney Carter were alive I would dare anyone to go to him and explain what he meant when he wrote the words.

Ask any singer songwriter that does the rounds and they will tell you that this does happen to them. It annoys them usually and they are too polite to disabuse the "knowing" - usually.

If you see a meaning in the words then you have to take ownership of the interpretation and be judged along with the originator.

To the pure, all things are pure.