answer:I am not a philosophy student, but I do speak French. I was unable to find the entire text of “Le Mythe de Sisyphe”, but I believe I found the sentence you are looking for: Son rocher est sa chose. I honestly don’t know how else to translate that other than “his rock is his thing.” Source in French (paragraph 6, third sentence). I missed part of your details when I posted the above. Chose does not have too many shades of meaning, it pretty much is just “thing” in a simple form (like an object or item). Reading the preceding sentences, I take it to mean that the rock is his destiny, it’s his “thing” in that it’s his sole purpose.