It is not a question of recuperation after a toilsome and well-done job. Even the Sabbath rest of man corresponding to the divine rest does not have this sense in the Old Testament, but means negatively a simple cessation and abstention from further work. The freedom, rest and joy of the Sabbath consist in the fact that on this day man is released from his daily work. On the Sabbath he does not belong to his work.Nor is it merely a question of having to recuperate from the work that lies behind him and to fortify himself for the new tasks that are ahead. On the Sabbath he belongs to himself. Whether he be farmer, artisan, servant or maid, he is just the man who for six days had to be these things and to perform the corresponding tasks, but whose being and existence are more than all these things and his work, who in and with these things seeks to be a man, male and female, and as such before God. That he does not strive in vain towards this goal; that his work cannot devour him but consists of steps towards this goal, is confirmed at the end of each week by the proffered freedom, rest and joy of the workless Sabbath which he is granted. It is this which gives perspective and depth, meaning and lustre, to all his weeks, and therefore to his whole time, as well as to the work which he performs in his time.
–Karl Barth, Church Dogmatics (ed. Geoffrey Bromiley and Thomas Torrance, Edinburgh: T and T Clark, 1958 E.T. of the German 1945 original) III.I.para. 41, Creation and Covenant, p. 214