Chapter 26 — Part III: The Decalogue — The Third Commandment
Section 22. Second Part of this Commandment — The second part of the precept declares that the seventh day was consecrated by God to His worship; for it is written: Six days shalt thou labour, and do all thy works; but on the seventh day is the sabbath of the Lord thy God. From these words we learn that the Sabbath is consecrated to the Lord, that we are required on that day to render Him the duties of religion, and to know that the seventh day is a sign of the Lord's rest.