Here are a few statements from Catholicism on the changing of the Sabbath.
Catholic Record (September 1, 1923):
“Sunday is our mark of authority…The [catholic] Church is above the Bible, and this transference of the Sabbath observance is proof of that fact.”
Chancellor Albert Smith for Cardinal of Baltimore Archdiocese, letter dated February 10, 1920:
“If Protestants would follow the Bible, they should worship God on the Sabbath day [which] by God is Saturday. In keeping the Sunday, they are following a law of the Catholic Church.”
The Convert’s Catechism of Catholic Doctrine (1957): 50:
“We observe Sunday instead of Saturday because the Catholic Church transferred the solemnity from Saturday to Sunday.”
Our Sunday Visitor (February 5, 1950):
“Practically everything Protestants regard as essential or important they have received from the Catholic Church… The Protestant mind does not seem to realize that in accepting the Bible and observing the Sunday, in keeping Christmas and Easter, they are accepting the authority of the spokesman for the church, the Pope.”
Louis Gaston Segur, Plain Talk about the Protestantism of To-Day (London: Thomas Richardson and Son, 1874): 213:
"Thus the observance of Sunday by the Protestants is a homage they pay, in spite of themselves, to the authority of the (Catholic) Church.
The Catholic Mirror (September 23, 1893):
“The Catholic Church, for over one thousand years before the existence of a Protestant, by virtue of her divine mission, changed the day from Saturday to Sunday…”
Catholic Priest T. Enright, CSSR, Kansas City, MO:
“It was the holy Catholic Church that changed the day of rest from Saturday to Sunday, the 1st day of the week. And it not only compelled all to keep Sunday, but at the Council of Laodicea, AD 364, anathematized those who kept the Sabbath and urged all persons to labor on the 7th day under penalty of anathema.”
Catholic Priest T. Enright, CSSR, lecture at Hartford, KS, Feb 18, 1884:
“I have repeatedly offered $1000 to any one who can furnish any proof from the Bible that Sunday is the day we are bound to keep…The Bible says, “Remember the Sabbath day to keep it holy,” but the Catholic Church says, “No, keep the first day of the week,” and the whole world bows in obedience.”
Letter from C.F. Thomas, Chancellor of Cardinal Gibbons on October 28, 1895:
“Of course the Catholic Church claims that the change was her act…And the act is a MARK of her ecclesiastical power and authority in religious matters.”
American Catholic Quarterly Review (January 1883):
“Sunday…is purely a creation of the Catholic Church.”
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Catholic American Sentinel (June 1893):
“Sunday…It is a law of the Catholic Church alone…”
“The Question Box,” The Catholic Universe Bulletin (August 14, 1942): 4:
“The (Catholic) Church changed the observance of the Sabbath to Sunday by right of the divine, infallible authority given to her by her Founder, Jesus Christ. The Protestant claiming the Bible to be the only guide of faith, has no warrant for observing Sunday.”