Gregory the Great

For hence it is said by the prophet, "The dead shall not live; the giants shall not rise up again." For whom does he call "the dead" except sinners, and whom does he designate "giants" except those who over and above take pride in sin. Now the former do "not live," because by sinning they have forfeited the life of righteousness; these latter too "cannot rise up again" after death because after their transgression they are swollen with pride and do not have recourse to the remedies of penitence.