“It shall come to pass in the latter days that the mountain of the house of the LORD shall be established as the highest of the mountains, and shall be lifted up above the hills; and all the nations shall flow to it, and many peoples shall come, and say: “Come, let us go up to the mountain of the LORD, to the house of the God of Jacob, that he may teach us his ways and that we may walk in his paths.” For out of Zion shall go the law, and the word of the LORD from Jerusalem. He shall judge between the nations, and shall decide disputes for many peoples; and they shall beat their swords into plowshares, and their spears into pruning hooks; nation shall not lift up sword against nation, neither shall they learn war anymore. O house of Jacob, come, let us walk in the light of the LORD.” (Isaiah 2:2-5)

“The earth mourns and withers; the world languishes and withers; the highest people of the earth languish. The earth lies defiled under its inhabitants; for they have transgressed the laws, violated the statutes, broken the everlasting covenant. Therefore a curse devours the earth, and its inhabitants suffer for their guilt; therefore the inhabitants of the earth are scorched, and few men are left.” (Isaiah 24:4-6)

“Give attention to me, my people, and give ear to me, my nation; for a law will go out from me, and I will set my justice for a light to the peoples. My righteousness draws near, my salvation has gone out, and my arms will judge the peoples; the coastlands hope for me, and for my arm they wait. Lift up your eyes to the heavens, and look at the earth beneath; for the heavens vanish like smoke, the earth will wear out like a garment, and they who dwell in it will die in like manner; but my salvation will be forever, and my righteousness will never be dismayed. “Listen to me, you who know righteousness, the people in whose heart is my law; fear not the reproach of man, nor be dismayed at their revilings. For the moth will eat them up like a garment, and the worm will eat them like wool; but my righteousness will be forever, and my salvation to all generations.” (Isaiah 51:4-8)

“I will take you from the nations and gather you from all the countries and bring you into your own land. I will sprinkle clean water on you, and you shall be clean from all your uncleannesses, and from all your idols I will cleanse you. And I will give you a new heart, and a new spirit I will put within you. And I will remove the heart of stone from your flesh and give you a heart of flesh. And I will put my Spirit within you, and cause you to walk in my statutes and be careful to obey my rules. You shall dwell in the land that I gave to your fathers, and you shall be my people, and I will be your God.” (Ezekiel 36:24-28)

“My servant David shall be king over them, and they shall all have one shepherd. They shall walk in my rules and be careful to obey my statutes.” (Ezekiel 37:24)

All of Ezekiel 43. Also Ezekiel 45:7 through Ezekiel 46:24 (Ezekiel 47:1-12 establishes the future setting) Here are a couple excerpts from Ezekiel 46 that show the observance of Sabbaths and appointed feasts:

“The people of the land shall bow down at the entrance of that gate before the LORD on the Sabbaths and on the new moons.” (Ezekiel 46:3)

“When the people of the land come before the LORD at the appointed feasts, he who enters by the north gate to worship shall go out by the south gate, and he who enters by the south gate shall go out by the north gate: no one shall return by way of the gate by which he entered, but each shall go out straight ahead. When they enter, the prince shall enter with them, and when they go out, he shall go out. “At the feasts and the appointed festivals, the grain offering with a young bull shall be an ephah, and with a ram an ephah, and with the lambs as much as one is able to give, together with a hin of oil to an ephah.” (Ezekiel 46:9-11)

“Then everyone who survives of all the nations that have come against Jerusalem shall go up year after year to worship the King, the LORD of hosts, and to keep the Feast of Booths. And if any of the families of the earth do not go up to Jerusalem to worship the King, the LORD of hosts, there will be no rain on them. And if the family of Egypt does not go up and present themselves, then on them there shall be no rain; there shall be the plague with which the LORD afflicts the nations that do not go up to keep the Feast of Booths.” (Zechariah 14:16-18)

“The Son of Man will send his angels, and they will gather out of his kingdom all causes of sin and all law-breakers, and throw them into the fiery furnace. In that place there will be weeping and gnashing of teeth. Then the righteous [law-obeyers] will shine like the sun in the kingdom of their Father. He who has ears, let him hear.” (Matthew 13:41-43)