Given Israel's stated goal in the war is destruction of Hamas, why did they attack the Gaza strip from the North instead of from the South? The latter seems more sensible since taking Rafah first would trap Hamas' fighters against the Mediterranean. By attacking from the North instead, Hamas' fighters could conceivably flee via Egypt.

I'm looking for any public statements about this by Israeli officials, if any have been made; or an explanation why this would not make military sense.