Genesis 2:2

(2) God ended his work.—Not all work (see John 5:17, and Note in loc.), but the special work of creation. The laws given in these six days still continue their activity; they are still maintained, and there may even be with them progress and development. There is also something special on this seventh day; for in it the work of redemption was willed by the Father, wrought by the Son, and applied by the Holy Ghost. But there is no creative activity, as when vegetable or animal life began, or when a free agent first walked erect upon a world given him to subdue.

The substitution, in the LXX. and Syriac, of the sixth for the seventh day, as that on which God ended His work, was probably made in order to avoid even the appearance of Elohim having put the finishing touches to creation on the Sabbath.