|The Sabbath is an important theological concept in the book of Isaiah. The significance attached to the Sabbath does not only find expression in the prediction of its observance in the renewed conditions following the captivity, but also in the fact that continual possession of the promised land would depend upon proper Sabbath-keeping. The final verses connect Sabbath-keeping with eschatology by implying that Sabbath will be observed in the "new heavens and new earth." Through contextual analysis, however, it is suggested that the eschatology in this text is best understood in a postexilic sense (i.e., an extended period following the return from captivity) rather than in an apocalyptic sense. Further, the creation of "new heavens and new earth" is to be understood as a highly poetic expression anchoring the redemption and restoration of Judah from the Babylonian captivity. Sabbath-keeping sums up righteousness.