It’s likely that the setting in Isaiah 56 is the land of Israel, i.e. the exiles have returned to their homeland. The Lord rebukes the Israelites for their unrighteousness – viz. keeping the Sabbath holy. Apparently they were profaning the Sabbath, i.e. not observing the prohibitions of the law regarding the Sabbath. More important, in a general sense, they were not setting the day aside for worship and rest, as a day dedicated to the Lord. In contrast, anyone who keeps the Sabbath is blessed. In fact, “anyone” refers not only to Israelites, but includes also those who by the Law have been excluded from special blessings of the God of Israel. Specifically, the foreigner and eunuch are mentioned, considered by the Law to be “outsiders.”
In fact, if the eunuch and the foreigner seek God, i.e. “observe my Sabbaths and choose what pleases Me and are faithful to My covenant,” they too will be blessed. They will get a name that’s better than sons and daughters, they will be brought to His holy mountain and be happy. Their offerings and sacrifices will be acceptable. In other words, they will be blessed as the Israelites are blessed. Anyone who seeks God cannot say he/she will be excluded from God’s people or be like a “dry tree.” This is an amazing thought given that Israel was to be set apart from the foreigners, who were considered unclean. Israel is a holy nation in contrast to the Gentiles.
In Isaiah, we see glimpses that God is not merely interested in blessing and saving Israel, but that He will save and blessed all peoples because He is the Creator of all peoples. In v. 7, it says, “. . . for my temple will be known as a temple where all nations may pray.” Verse 8 continues this thought that God will save other peoples, not just Israel. “Thus says the Lord God, who gathers the outcasts of Israel, I will gather others to them besides those already gathered.” Earlier in Isaiah 49, God makes an even stronger statement regarding the salvation of all peoples.
And now the Lord says, who formed Me in the womb to be his Servant,
to bring Jacob back to him, and that Israel might be gathered to Him,
for I am honored in the sight of the Lord, and my God has become my strength—
He says,“It is too light a thing that You should be my Servant
to raise up the tribes of Jacob and to restore the survivors of Israel;
I will give You as a light to the nations, that My salvation may reach to the end of the earth.” Isaiah 49:5-6 (NET)
In today’s context, you might say that we (believers) are a light to the nations, which includes the refugees from many countries fleeing war, persecution, and famine. God is bringing the nations to us. What will we do with them? God is not interested in saving only Israel or Americans. God’s plan is to have people from every tongue, tribe, and nation bowing before Him.
After these things I looked, and here was an enormous crowd that no one could count, made up of persons from every nation, tribe, people, and language, standing before the throne and before the Lamb dressed in long white robes, and with palm branches in their hands. They were shouting out in a loud voice, “Salvation belongs to our God, who is seated on the throne, and to the Lamb!” Rev. 7:9-10 (NET)