One liner to download and install emacs lisp source code

Run the below command in shell,

curl http://ftp.gnu.org/gnu/emacs/emacs-`emacs --version|head -n1|sed 's/[^0-9.]*\([0-9]\+\.[0-9]\+\).*/\1/g'`.tar.gz | sudo tar --exclude=admin/* --exclude=etc/* --exclude=nt/* --exclude=doc/* --exclude=leim/* -C /usr/share/emacs/`emacs --version|head -n1|sed 's/[^0-9.]*\([0-9]\+\.[0-9]\+\).*/\1/g'`/lisp/ --strip-components=2 --wildcards -zxv *.el

For example, after installing the lisp code. You can M-x find-function package-list-packages in Emacs, you will jump to the definition of that command in "/usr/share/emacs/24.3/lisp/emacs-lisp/package.el" (I assume your emacs version is 24.3).