I would like to know if there are some references in which heidegger treats the word life. What does Heidegger say about life, and where?
Heidegger uses the word Life (Leben) all over the place (it appears at least once in every volume of the GA), as do most of us, but the word itself doesn't appear to have a special place in his terminology. In places he refers to other philosophers' use of the word (Aristotle, Hegel). He looks at some related etymology; e.g., Er-Leben.