Have you ever found the description of how Gurnemanz is laying Parsifal's arm around his neck and then laying his own hand around Parsifal's body a bit strange?
This detailed stage instruction in Wagner's libretto (just before they are entering the great hall of the Grail Castle) has always puzzled me. It think it has to do with the close bodily contact between the young Parsifal and the older man, being strangers to one another. I mean, I would probably find it mighty peculiar if an elderly man did the same to me before entering, say, a church to show me around.
The text says (with English translation taken from Monsalvat.no):
Er hat Parsifals Arm sich sanft um den Nacken gelegt und dessen Leib mit seinem eigenen Arme umschlungen; so geleitet er ihn bei sehr allmählichem Schreiten.
(He has gently laid Parsifal's arm around his neck and puts his own arm around his body; thus he leads him with very slow steps.)