So, I recently was reading something and I found the structure そのものだ, which at first glance it is not quite mean "that thing" as I thought, and the best explanation of it that I could find was in the "A dictionary of Advanced Japanese grammar", and from what I saw, after a noun, it is translated as "itself" or "the picture of/the embodiment of~ (health, beauty etc.)
The book said that after a Na-adjective such as in the examples taken from the book
温厚そのものだ (s.o is very gentle)
温厚そのものの人柄 (a very gentle personality)
In these examples, 'sono mono' is just used to place more emphasis? (If you could provide me with more examples it would be great, because most of the ones that are in the book and what I saw on websites, they are usually translated with the meanings itself" or "the picture of/the embodiment of~ like I mentioned.
My sentence was like this:
(someone is narrating and holding an object that belonged to Sakura, which the narrator knew she was attached to it, but after a painful event, Sakura abandoned it, a metaphor for throwing away her sentimentality)
and I think here it could translate as:
"Sakura threw (this-the item) the very embodiment of her sentimentality"
I hope I could explain well enough!