Sabbath was established in the garden of Eden, and was kept all through the Bible, even after Jesus died. Here is a verse from before the 10 commandments:
Exodus 16:22 Now on the sixth day they gathered twice as much bread, two omers for each one. When all the leaders of the congregation came and told Moses, 23 then he said to them, “This is what the LORD meant: Tomorrow is a sabbath observance, a holy sabbath to the LORD.
Then, these are from after Jesus died:
Acts 13:42 As Paul and Barnabas were leaving the synagogue, the people invited them to speak further about these things on the next Sabbath.
Acts 17:2 As his custom was, Paul went into the synagogue, and on three Sabbath days he reasoned with them from the Scriptures,
Acts 18:2 There he met a Jew named Aquila, a native of Pontus, who had recently come from Italy with his wife Priscilla, because Claudius had ordered all the Jews to leave Rome. Paul went to see them, 3 and because he was a tentmaker as they were, he stayed and worked with them. 4 Every Sabbath he reasoned in the synagogue, trying to persuade Jews and Greeks.
There are ceremonial laws (Mosaic Law), and God’s written laws. The ceremonial laws were written by Moses, but the 10 commandments were written by God’s own finger and permanent.
Exodus 31:18 When He had finished speaking with him upon Mount Sinai, He gave Moses the two tablets of the testimony, tablets of stone, written by the finger of God.
And Jesus tells us they are to be kept as long as the earth exists, and being such pure laws, I know that they are eternal, forever…
Matthew 5:17 “Do not think that I came to abolish the Law or the Prophets; I did not come to abolish but to fulfill. 18 “For truly I say to you, UNTIL HEAVEN AND EARTH PASS AWAY, NOT THE SMALLEST LETTER OR STROKE SHALL PASS FROM THE LAW until all is accomplished. 19 “Whoever then annuls one of the least of these commandments, and teaches others to do the same, shall be called least in the kingdom of heaven; but whoever keeps and teaches them, he shall be called great in the kingdom of heaven.
Has all been accomplished? Heaven and earth did not pass away, we’re still here. This is what Jesus said, to deny it is to deny Christ.
The 7th day Sabbath was and is still the true Sabbath.