The reference has nothing to do with the Sabbath.
The Sabbath is undeniably especially chosen by God, not by man. It existed before sin. It existed before Sinai as enroute to the mountain Manna fell on all days except the Sabbath, and a double portion on Friday which did not spoil overnight. When they went out to collect on the Sabbath God asked “how long will you disobey my commandments”.
The new testament spends a considerable number of pages and chapters discussing circumcision and it’s irrelevance to christians. What kind of a ruckus do you think would have ensued if the new christians had in any way attempted to ignore the Sabbath? The total lack of brouhaha over this issue speaks volumes.
Why is the name for Saturday in so many diverse languages “Sabbath”? Greek, Latin, Spanish, Italian, French, Russian, Persian, Polish, Arabic, Turkish, Malay, Hindustani, and on and on and on.
Do you think this was out of deference for the Jews, a way all nations showed their respect for the Israelites?
Even Babylonian Syriac, Chaldee Syriac and Ancient Syriac name it Sabbath.
Never, not even once, does the Bible ever command Sunday observance.
If you call yourself a Christian it is impertinent to make a part of your faith something that Christ never taught.
No, the cloud of evidence is so overwhelming that no one should be in any doubt as to the perpetuity of all the commandments, including the 4th. To think that Paul would set himself up against God to call “the” Sabbath a day that was something we could choose or discard at will, is unthinkable.
Many accuse Adventists of making a huge issue of a small matter when it comes to the Sabbath.
But they forget that all the bible was written by men. Moved by the Holy Spirit, yes. But one glaring exception. Only one single piece of the entire Bible was written by God himself. On stone. When Moses smashed the commandments over the Israelite idol worship, God instructed him to return and God wrote them himself a second time.
Is it Adventists who make the commandments unique and especially holy above all else?
Or is it God?
The confusion stems from those who read with only the intention of denying the overwhelming evidence. They read the way a drunk uses a lamppost, for support rather than illumination.
Edit
A comment from Lesley is about when the Sabbath begins and ends. Is is at sundown as the Jewish nation recons it? A second question is are we still under the ceremonial law? These are valid concerns because they closely relate to the Sabbath question.
From before sin, as the first creation, at the creation of the day's themselves, they were measured from evening to evening. The Jewish nation has always kept to that. It has as a consequence no bearing on or relationship with the ceremonial law.
The ceremonial law relates to the systems that prefigured Christ and the plan of salvation through Christ. They were instituted at the gates of Eden after Adam and Eve sinned. Abel as you know offered a sacrifice according to the law, and it was accepted. Cain wished to substitute the lamb with vegetables because he was a farmer not a shepherd as Abel was. God rejected his. Jesus was not to be prefigured by vegetables.
These systems ceased at the hour of Jesus death, signified by the tearing of the veil at that moment. No sacrificial offering was to occur again. The blood of bulls and goats and lambs ceased when type met anti-type and Jesus shed His perfect blood. With the sacrificial system went the priesthood, the temple, the altar, all the symbols. None had any meaning if you no longer performed a sacrifice and had blood to carry. No lamb to confess your sins over. With it went the day of atonement and all the other ceremonies.
BUT. They were lesson books to us of the plan of salvation. Each of those feasts and ceremonies teach us a lesson about how God is working for us. The Temple layout and the day of atonement in particular hold highly relevant lessons for us today. So though we are to no longer practice them, we are to look at them and read them and see the lesson they teach.
I will very briefly allude to the Temple. The layout of the Temple tells the plan of salvation. It begins in the courtyard (the world), outside the temple itself and it begins at the altar. Without Jesus, there is no plan. His blood is required for the plan of salvation to be possible. Everything starts there for He alone is the Way by which we may approach God with our sins forgiven. Next is the Laver, this symbolises baptism. It too, is outside the Temple, in the world. Here we publicly announce our allegiance to God, and join with Jesus symbolically in His death and His resurrection.
The true temple itself is in Heaven. Read Revelation and you see there the Seven Candlesticks, the Table of Shewbread, the Altar of Incense and finally, the Ark of the Covenant. All these you find mentioned in Revelation.
Additionally, as the True High Priest, it begins with Jesus walking amongst the candlesticks, trimming the wicks and supplying them with oil. If you study further you see Him progress through Revelation to the Table of Shewbread, the Altar of Incense and finally the presence of God at His throne. This occurs in order.
But I will stop there else this edit to the answer becomes detached from the original answer. This edit exists merely to show that the sacrificial system and all that related to it, the ceremonies, the temple and the earthly priesthood ceased at the cross, but that they are still and always will be relevant via the lessons they taught. These Ceremonial Sabbath's ceased. The weekly Sabbath, "The Sabbath" is not part of them.
So, the Sabbath begins as all days do, at sunset and proceeds until sunset the next day and this has no relationship to the sacrificial and ceremonial laws. (Ask any mother and she will tell you Sunday night as we call it, is a school night. Your performance and preparation for the day ahead begins with your rest the night before.)
This is why the Sabbath was on the tables of stone with the other moral laws, and is not part of the ceremonial law.