Grimrock

For the iron door on Level 5, I read a scroll with the hint "Those who are patient and rest in the gaze of the dragons"

As far as I know, there are only 2 dragon lookng statues on level 5. What I've done already is rest right in front of them separately, and rest in where their gazes intersect with each other. However, non of my actions have open the doors thus far. What am I missing?

For me, resting in the spot where their gazes intersect worked, but I had to rest for a while - you have to let the dragons take a good look at you.