"Now the Scriptures alone do not contain all the truths which a Christian is bound to believe, nor do they explicitly enjoin all the duties which he is obliged to practice. Not to mention other examples, is not every Christian obliged to sanctify Sunday and to abstain on that day from unnecessary servile work? Is not the observance of this law among the most prominent of our sacred duties? But you may read the Bible from Genesis to Revelation, and you will not find a single line authorizing the sanctification of Sunday. The Scriptures enforce the religious observance of Saturday, a day which we never sanctify."
—Faith of Our Fathers, Cardinal Gibbons, p. 72
But what does the HOLY FATHER in heaven say? But the seventh day is the sabbath of the LORD thy God: Exodus 20:10