Charles Ellicott Commentary Exodus 23:12

"Six days thou shalt do thy work, and on the seventh day thou shalt rest; that thine ox and thine ass may have rest, and the son of thy handmaid, and the sojourner, may be refreshed." — Exodus 23:12 (ASV)

The law of the weekly Sabbath is here repeated in conjunction with that of the Sabbatical year, to mark the intimate connection between the two, which were parts of one and the same system—a system which culminated in the Jubilee year (Leviticus 25:8–13). Nothing is added to the requirements of the fourth commandment; but the merciful intention of the Sabbath day is more fully brought out—it is to be kept in order that the cattle may rest, and the slave and stranger may be refreshed.