Gurnemanz thinks Parsifal is to be the deliverer of Amfortas. And to Parsifal's question, "Who is the Grail?" Gurnemanz answers:

That I won’t tell; but if thou who seeks of Him has been hidden,
From theyself the truth will not stay hidden

I think thy face I rightly knew.
The land to Him no path leads through,

And search but severs from Him wider,
When He Himself is not its guider.


What is the significance of Gurnemanz's reply to Parsifal's question: "Who is the Grail?"