"It is evident from the reading of the fourth commandment that the Sabbath did not originated at Sinai, for we are referred to the creation of the earth, and told that at the conclusion of that work God “blessed” and “hallowed” the Sabbath day (Ex. 20:11).
----It must, therefore, have been in existence at that time;
a thing that has no existence cannot be blessed,
neither can it be hallowed."
E.J. Waggoner