Rest of God
The principle underlying the Sabbath is formulated in the Decalogue itself. It consists in this, that man must copy God in his course of life. The divine creative work completed itself in six days, whereupon the seventh followed as a day of rest for God. In connection with God, ‘rest’ cannot, of course, mean mere cessation from labour, far less recovery from fatigue. Such a meaning is by no means required by the Old Testament usage of the word. ‘Rest’ resembles the word ‘peace’ in this respect, that it has in Scripture, in fact to the Shemitic mind generally, a positive rather than a negative import. It stands for consummation of a work accomplished and the joy and satisfaction attendant upon this. Such was its prototype in God.
Geerhardus Vos, Biblical Theology: Old and New Testaments (Eugene, OR: Wipf and Stock Publishers, 2003), 139-140.