The chapter starts with a call to righteousness. It doesn’t expressly say to “keep the commandments”. Rather it says to keep judgment, and do justice. Then there is the reminder that the Salvation of the Lord is near at hand. There is a second distinguishing characteristic of those who would do righteousness: they keep the sabbath day from polluting it. What would pollute the Sabbath day? The commandment for the Sabbath day is to “keep it holy”.
This is a chapter of inclusion. Isaiah identifies two different case scenarios of people who might feel excluded from the fold of God: eunuchs and the sons of the stranger. Clearly we are not dealing with children of the House of Israel in either case. Verses 4 & 5 explains that eunuchs that 1) keep the sabbath, 2) do the will of God, and 3) make covenants with God, these shall receive a place and name within the temple (mine house).
A similar scenario is repeated with the sons of the stranger in verses 6 & 7:
- they join themselves to the Lord
- they serve Him
- they love the name of the Lord
- they are His servants
- they (everyone of them) keep the Sabbath day from polluting it
- and finally, they make covenants with Him.
These are then promised to be brought into his holy mountain, and to made joyful in his house of prayer.
There is a powerful prophecy at the end of this verse 7: “for mine house shall be called an house of prayer for all people.”
Near the end of the chapter is an observation of those that are called to be “watchmen”. Isaiah calls them blind and dumb dogs. He also calls them greedy dogs, shepherds that cannot understand. These are harsh words of accusation and a reminder to not be found sitting on my laurels.