Exodus 16:23

To-morrow is the rest of the holy sabbath— It is amazing to observe to what length an attachment to systems and opinions sometimes carries men. This is evident from the method in which this passage is interpreted by those who have entertained peculiar notions respecting the sabbath. Nothing can be plainer, from this whole chapter, than that the seventh day was now held sacred as a day of holy rest unto the Lord. In order to preserve it sacred, the Lord makes this remarkable disposition concerning the manna; the falling of which is regulated by the known and established law of the sabbath, which is here spoken of as a period perfectly familiar and customary to the people: and indeed there seems no reason to doubt, that the sabbath-day was held sacred by the people of God from its very first institution, when God finished his works of creation, and sanctified the seventh day. And this may very well and truly account for its institution's not being mentioned again by the sacred historian; the observation of it having always continued from the beginning, and therefore the mention of it being as unnecessary as that of any other common and generally allowed principle in religion. They who are inclined to see more on this subject may consult Hallet's Notes on Scripture, vol. 3: p. 100.