Êxodo 31

Êxodo 31:15

They were also commanded to keep the holiday of the Sabbath one day in the week, so as to be subjected to no burthen, and I would that being thus released from earthly works they had escaped, carrying with them to that perpetual sabbath of future ages the burthen of heavy crimes. But as God knew how prone to fall the people were, He enjoined a part upon the weaker by the observance of one day, He reserved the fulness for the stronger: the Synagogue observes the day, the Church immortality. In the Law therefore is a part, in the Gospel is perfection. — Letter 74.5