Remember the sabbath day. The institution of the sabbath dates, at any rate, from the giving of the manna (Exodus 16:23). Its primeval institution, which has been thought to be implied in Genesis 2:3, is uncertain.
The word "remember" here may be simply a reference to what passed in the "wilderness of Sin" as related in Exodus 16:22-30. On the sabbath itself, both Jewish and Christian, see the comment upon that chapter.