Chapter 26 — Part III — The Ten Commandments
Section 541. Q. Is there not yet something more to be understood under the name of the seventh day, or Sabbath? A. As in the Church of the Old Testament the name Sabbath was understood to include divers other days appointed like the Sabbath for festivals or fasts, as the festival of the Passover, and the day of Atonement, so likewise are we now in the Christian Church bound to keep, besides the Lord's Day, certain others also, which have been appointed as festivals to the glory of God and the honor of the Blessed Virgin and other saints, or as days of fasting. (See Orthod. Confess. Pt. III. Q. 60; Pt. I. Q. 88.)