Six days may work be done; but on the seventh is the sabbath of rest, holy to the LORD: whosoever does any work on the sabbath day, he shall surely be put to death.
Read Chapter 31
Ambrose of Milan
They were also commanded to celebrate the sabbath as a feast on one day of the week, so that they would not be subjected to any burdens. Would that they, who were freed from worldly labors, have departed in such a way. That they would not carry with themselves any burdens of serious sin into that perpetual sabbath of ages to come. But since God knew that the people were fickle, he prescribed for the more feeble a part [of that sabbath] by the observation of one day; he reserved its fullness for the stronger. The synagogue observes a single day; the church observes a day without end. In the law then is the part; in the gospel there is completion. ()..
Indeed by the fleshly sabbath, which was kept according to the letter, the people were ordered to keep free from all servile work on the seventh day. [The meaning of] the spiritual sabbath, in the light of the sevenfold spiritual grace which we have received, is that we should remain on holiday from the unrest of vices not only on one day but every day. For if, according to the Lord’s voice, “Everyone who commits sin is a servant of sin,” it is clear that sins are properly understood as servile works, and we are ordered to walk free of them, as it were on the seventh day, in the partaking of spiritual grace. [We are ordered] not only to keep from wrong deeds but also to devote ourselves to good deeds.