Grimrock

There are two doors I haven't opened. Holy Scriptures and Outer Sanctum. I have a golden key, but it doesn't fit the sanctum lock. I've gotten past the hallway with the text from this forum, but I feel like I am missing the source of it. I assume it is in the Holy Scriptures room which I have not been able to open. Past the hallway, all I found was a skill book and a couple of bugs. I feel like I am missing something there as well.

attack the wall with the painting, under them you find hidden switch to open the doors/items.