ectypal.net

The moral law (which is the pattern of God’s image in man) ought to correspond with the eternal and archetypal law in God, since it is its copy and shadow (aposkimation), in which he has manifested his justice and holiness. Hence we cannot conform ouselves to the image of God (to the imitation of which Scripture so often exhorts us) except by regulating our lives in accordance with the precepts of this law. So when its observation is enjoined, the voice is frequently heard, “Be ye holy, for I am holy.” Now this law is immutable and perpetual. Therefore the moral law (its ectype) must necessarily also be immutable.