28. Compare Heb 2:2, 3; 12:25.
despised—"set at naught" [Alford]: utterly and heinously violated, not merely some minor detail, but the whole law and covenant; for example, by idolatry (De 17:2-7). So here apostasy answers to such an utter violation of the old covenant.
died—Greek, "dies": the normal punishment of such transgression, then still in force.
without mercy—literally, "mercies": removal out of the pale of mitigation, or a respite of his doom.
under—on the evidence of.