He forgot by the bedside the strange book from where his prayers were read.
Does it mean:
Lying on bed, He forgot the strange book. This book is the one which he read his prayers from?
I'm not sure if "forget by the bedside" means that "as he sleeps on the bed, he forgot the book", or "he forgot the book when he was next to the bed".
It is saying that there is a strange book that he reads prayers from, and that he forgot this book and left it lying beside his bed (maybe on a table next to the bed, or on the floor, etc).
The phrase "forgot by the bedside the strange book" might be easier to understand if you expanded it into the equivalent sentence "forgot about the book and left it by the bedside".
The phrase "from where" is a prepostional phrase that indicates where he reads his prayers from (the strange book).
