"Let us now consider this subject in the light of Holy Scripture: and here I remark that it would appear strange indeed, that in the midst of a code of moral laws, intended to be of perpetual obligation, we should find one, and but one, of a merely ceremonial and temporary nature; and this without the smallest intimation that it was of a character different from the rest. There was, moreover, a marked difference between the manner in which the ten commandments were given, and that which was adopted in instituting the temporary ritual of the Hebrews. The ten commandments were uttered by an audible voice of Jehovah from Mount Sinai; and were also engraved by the finger of God on two tables of stone, which were to be laid up in the ark, and preserved with it in the most holy place. Not a single ceremonial institution, unless the fourth commandment is one, was given in this manner—a manner clearly intended to denote that those laws possessed a dignity and perpetuity of character, which did not belong to the ceremonial rites. These rites were indeed given by divine inspiration to Moses, and till the advent of the Saviour, were doubtless as binding on the Jews, as the precepts of the Decalogue. But the different manner in which they were promulged and preserved, seems clearly to intimate the Divine appointment, that the latter should be temporary, and the former perpetual...
From these considerations, and some others of a similar nature, which I do not think necessary to specify, we conclude, that the fourth commandment ought, beyond a question, to be regarded as a part of the moral law—equally obligatory, and as perpetual in its nature and design, as any other precept of the decalogue.
We are aware that those who represent the Jewish Sabbath as a ceremonial institution, endeavour to support their hypothesis by what the apostle says, Coloss. ii. 16,17. "Let no man, therefore, judge you in meat, or in drink, or in respect of a holy day, or of the new moon, or of the Sabbath days; which are a shadow of things to come; but the body is of Christ." But when we consider that the writer of these words was in the practice of observing a particular day of the week, for special religious exercises, as is apparent from his epistles, as well as from the Acts of the Apostles, we cannot believe that he meant to condemn this practice. He would, by so doing, have condemned himself. By the Sabbath days, which are a shadow of things to come, he plainly means the Jewish festivals, in which holy convocations were held; and which are often in the Old Testament denominated Sabbaths. Indeed, it seems evident at once, by the enumeration in this passage of rites confessedly ceremonial, that the apostle is speaking exclusively of them. And accordingly, this prohibition is directed to Sabbath days, in the plural number, and not to the weekly Sabbath, which would have been mentioned in the singular, if that had been his object."
-- From his Lectures on the Shorter Catechism, Volume 2
