get_old_commits.txt

git checkout <commit> <file>
	Check out a previous version of a file. This turns the <file> that resides in the working directory into an exact copy of the one from <commit> and adds it to the staging area.

git checkout <commit>
	Update all files in the working directory to match the specified commit. You can use either a commit hash or a tag as the <commit> argument. This will put you in a detached HEAD state.