Isaiah 56:2

That keepeth the sabbath from polluting it... — It lies in the nature of the case that a devout king like Hezekiah would be an observer of the Sabbath. It is almost certain that the counsellors of the young Manasseh (probably the Shebna party), abandoning the religion of Israel in other things, would also disregard this. I take the prophet’s teaching accordingly as directed against that evil. He utters his beatitude for those who are faithful to the régime of Hezekiah’s reign, even though their alien birth or their condition as eunuchs seemed to exclude them from the polity of Israel (Deuteronomy 23:1).