Sforno on Exodus 21:14/ספורנו על שמות כ״א:י״ד

1מעם מזבחי, even though at that time when no cities of refuge existed yet the entire camp of the Levites, and not only the immediate area of the altar served as such a place of refuge.

2תקחנו למות, as in Jeremiah 7,11 “do you consider My house to be a den of thieves?