The subject this week is the theology of the sabbath according to Isaiah. Isaiah’s theology of the sabbath comes up most specifically in chapters 56-58. The major theme of the book is that God disciplined Judah as a loving Father to place them back on the path of righteousness. The issue specifically here is that Judah departed from the way of the Lord by “profaning the Sabbath” (56:2). Isaiah corrected their thinking and practice by showing them how the Sabbath is a means God uses by which He applies the blessings of the covenant of grace. The purpose for which Isaiah aimed was that Judah, and all nations would practice the means of grace of keeping the sabbath holy, for the ultimate aim of their receiving of the blessing of imputed righteousness of God by faith.
Isaiah 56:1 is a call to come back onto the path of righteousness to wayward Judah. The reason is because God’s righteousness is about to be revealed. That is the righteousness of God imputed by faith. Verse 2 showed the background issue requiring such a call to return to the way, namely, they had profaned the sabbath. Profaning the sabbath means doing sin of what is common to normal life on the day set apart for God’s holy ceremonial worship and service. Sin is an obvious wrongdoing on the Lord’s Day. Common life is not evil, but it is evil if it takes the place of the Lord’s holiness on the holy day. On the Lord’s Day, then the ethic is to keep the day holy; that is, devoted to worship and the service of God.
56:2 spoke about the blessing of the Lord’s sabbath, which is the blessing to the man who takes hold of the sabbath. The blessing in the book of Isaiah, as with the rest of the OT is the blessed estate in which one stands as a justified sinner (see Rom. 4, Gen. 12:1-3, Gen 15:6, or Psa. 32 or 24:5). Justification creates the blessed estate.
In verses 3-8 then Isaiah opens up the sabbath to the eunuch and the gentiles. He offered them free mercy through that means of grace. Both eunuchs and gentiles were excluded from the temple worship in the law of Moses, so their inclusion here is nothing less than them partaking in the covenant of grace by faith (56:4). Imagine the surprise of the Ethiopian Eunuch from the Queen’s court in Acts 8 who was converted by reading Isaiah 53, and who would have well known that while in Jerusalem he was not allowed to enter the temple, being a gentile and a eunuch. He would have read on only a few lines on the scroll and found this promise of grace.
Isaiah 58:13-14 concludes the section with a promise that if one treat the sabbath as a delight, that one will be granted the blessing and inheritance of Jacob, which is the kingdom of the age to come. We may not call it a delight today, but we who are gentiles should, that we may have the blessing of it.