The Third Commandment to keep Sunday holy is Divine Law
Not exactly. I don't mean to derail this thread, but the Divine Law of the 3rd Commandment is to keep the Sabbath day holy. When the Law was instituted and written, that day was on Saturday. The Catholic Church, using the Keys of Heaven given to Peter, changed that day to Sunday. Nonetheless, the Law is to keep the Sabbath day holy, not Sunday per se.