Can a French-speaking philosophy student help me with a question about Camus?

I’m working on Camus’s essay The Myth of Sisyphus for a class. The second sentence of the next-to-last paragraph says: “His rock is his thing.”

My translation is from a 1955 edition that predates the happy 1960s concept of “doing your own thing” and saying that something is or is not your “thing.”

So what I’d like to know is what this sentence says in the original French: not a translation from English to French but Camus’s own original words. Do you know how to get hold of them?

And then I want to know the dimensions and shades of meaning there are to that particular word for “thing” in French. This will help me gain an understanding of what Camus means by it.

Please note here that I am not asking for explications of Camus or help understanding his philosophy. I am interested in finding out what he actually said in this one sentence.