Which passages of Scripture are canonically or typically cited by Seventh-day Adventists in defense of the belief that evangelized Gentiles are to keep the Sabbath (sunset Friday to sunset Saturday) the same as the Jews in the Old Covenant? How do they normally interpret those passages in order to come to that conclusion?
Traditionally, Seventh-day Adventists hold that the Ten Commandments (including the fourth commandment concerning the sabbath) are part of the moral law of God, not abrogated by the teachings of Jesus Christ, which apply equally to Christians.
Following are excerpts from the Seventh-day Adventist Church regarding Sabbath:
The gracious Creator, after the six days of Creation, rested on the seventh day and instituted the Sabbath for all people as a memorial of Creation. The fourth commandment of God’s unchangeable law requires the observance of this seventh-day Sabbath as the day of rest, worship, and ministry in harmony with the teaching and practice of Jesus, the Lord of the Sabbath. The Sabbath is a day of delightful communion with God and one another. It is a symbol of our redemption in Christ, a sign of our sanctification, a token of our allegiance, and a foretaste of our eternal future in God’s kingdom. The Sabbath is God’s perpetual sign of His eternal covenant between Him and His people. Joyful observance of this holy time from evening to evening, sunset to sunset, is a celebration of God’s creative and redemptive acts. (Gen. 2:1-3; Exod. 20:8-11; 31:13-17; Lev. 23:32; Deut. 5:12-15; Isa. 56:5, 6; 58:13, 14; Ezek. 20:12, 20; Matt. 12:1-12; Mark 1:32; Luke 4:16; Heb. 4:1-11.)
Adventists believe that the formal giving of the Law to Israel does not indicate that Israel alone is morally responsible before God for the things represented in the law:
The great principles of God’s law are embodied in the Ten Commandments and exemplified in the life of Christ. They express God’s love, will, and purposes concerning human conduct and relationships and are binding upon all people in every age.
The basis of Adventist belief that the 4th commandment applies to all people in every age is that the Sabbath is first described in the creation account wherein God Himself rested. This Sabbath memorial of what God has done in creation is embodied in the Law and exemplified in Christ and, by extension, the Church (Christ's body, Christ's bride, God's people):
the Lord made “the heavens and the earth, the sea, and all that is in them” and rested on the seventh day. Thus He established the Sabbath as a perpetual memorial of the work He performed and completed during six literal days
It appears that, rather than making a distinction between the universal moral law and the Ten Commandments given to Israel through Moses, SDA holds them to be one and the same. The following excerpts are taken from the doctrine section of an SDA apologetic s website.
Seventh-day Adventists are in full accord ... that the moral law is eternal in its very nature and has not been abrogated. We believe that these eternal moral principles are unchanged and unchangeable. We further believe that these basic principles are found in the Decalogue—Ten Commandments, or the moral law.
Some think of the Sabbath as an institution related only to the Hebrews. Those who press this point claim that the Deuteronomy version of the Decalogue emphasizes that the Sabbath was given exclusively to the Hebrews, because they had been delivered from slavery.
The silence of the latter part of Genesis regarding the Sabbath is understandable when one remembers that acquaintance of the patriarchs with God's commandments was taken for granted. The author of the historical record in Genesis did not deem it necessary to mention it in his sweeping survey of the centuries. But Abraham kept the commandments of God (Gen. 26:5)—the Hebrew word here used for "commandments" being the same as that used for the Decalogue in Deuteronomy 5:10, 29. Kalisch mentions this as the law written in the heart of man, and the Pulpit Commentary states that the word means "that which is graven on tables." Abraham acknowledged and obeyed the moral law of God. If so, would that not include the Sabbath? The Companion Bible (Gen. 26:5) says Abraham had a charge, to be observed; commandments, to be obeyed; statutes (decrees), to be acknowledged; and laws "instruction," the Torah), to be followed.
And during their wilderness experience, God tested His ancient people as to whether they would walk in the way of His commandments (Ex. 16:4). The test came on the subject of the Sabbath. And comparison of Exodus 16:1 with Exodus 19:1 shows that this occurred several weeks before the promulgation of the Decalogue. They must, therefore, have known not only of God's law but also of specific commandments embraced therein, as evidenced by this reference to the Sabbath.
What is the biblical basis for the belief by Seventh-day Adventists that evangelized Gentiles should keep the Sabbath?
First of all let us look at the Biblical Sabbath.
The sabbath was first described in the biblical account of the seventh day of creation. Observation and remembrance of the sabbath is one of the Ten Commandments (the fourth in the Eastern Orthodox and most Protestant traditions, the third in Roman Catholic and Lutheran traditions). Most people who observe the first-day or seventh-day sabbath regard it as having been instituted as a perpetual covenant: "Wherefore the children of Israel shall keep the sabbath, to observe the sabbath throughout their generations, for a perpetual covenant." (Exodus 31:13-17) (see also Exodus 23:12, Deuteronomy 5:13-14) This rule also applies to strangers within their gates, a sign of respect for the day during which God rested after having completed creation in six days (Genesis 2:2-3, Exodus 20:8-11).
Seventh-day Adventists are not unique in their desire to go back to the biblical origins of keeping Saturday as a day dedicated to God. Many others do so.
In contrast to the majority of Christian denominations, Seventh Day churches see the adoption of Sunday as the Sabbath as a late development that would not have been recognised by the Early Church. Seventh Day Adventist theologian Samuele Bacchiocchi argued for a gradual transition from the Jewish observation of the Sabbath on Saturday to observation on a Sunday. His contention was that the change was due to pagan influence from the pagan converts, to social pressure against Judaism, and also to the decline of standards for the day. From Sabbath to Sunday (1977), He claims that the first day became called the "Lord's Day" as that was the name known as the sun-god Baal to the pagans so they were familiar with it and put forth by the leaders in Rome to gain converts and got picked up by the Christians in Rome to differentiate themselves from the Jews, who had rebelled, and the Sabbath. According to Justin Martyr (lived 100 to 165), Christians also worshiped on Sunday because it "possessed a certain mysterious import". Seventh-day Adventists point out the role played by either the Pope, or by Roman Emperor Constantine I in the transition from Sabbath to Sunday, with Constantine's law declaring that Sunday was a day of rest for those not involved in farming work.
Early Christian observance of both the spiritual seventh-day sabbath and a Lord's Day assembly is evidenced in a letter from Ignatius of Antioch to the Magnesians c. 110. The Pseudo-Ignatian additions amplified this point by combining weekly observance of a spiritual seventh-day sabbath with the Lord's assembly. If Pseudo-Ignatius dates as early as 140, its admonition must be considered important evidence on 2nd-century sabbath and Lord's Day observance. According to classical sources, widespread seventh-day sabbath rest by gentile Christians was also the prevailing mode in the 3rd and 4th centuries.
The "Sabbath in Africa Study Group" (SIA), founded by Charles E. Bradford in 1991, holds that the sabbath has existed in Africa since the beginning of recorded history. Taddesse Tamrat has argued that this practice predates Saint Ewostatewos's advocacy of observing both Saturday and Sunday as days of sabbath, which led to his eventual exile from Ethiopia around 1337. Emperor Zara Yaqob convened a synod at Tegulet in 1450 to discuss the sabbath question.
Sects, such as the Waldenses, retained sabbath observance in Europe during the Middle Ages. In Bohemia, as much as one quarter of the population kept seventh-day the sabbath in 1310. This practice continued until at least the 16th century, when Erasmus wrote about the practice.
At the time of the Protestant Reformation some Anabaptists, such as Oswald Glaidt, argued that the seventh day should be observed as the sabbath and that Sunday sabbath was an invention of the Pope.
Seventh-day Sabbatarianism was revived in 17th-century England. Early advocates included the Elizabethan Seventh-Day Men, the Traskites (after John Traske, 1586–1636), and Thomas Brabourne. The majority of seventh-day Sabbatarians were part of the Seventh Day Baptist church and experienced harsh opposition from Anglican authorities and Puritans. The first Seventh Day Baptist church in the United States was established in Rhode Island in 1671.
The Seventh-day Adventist Church is the largest modern seventh-day Sabbatarian denomination, with 18,778,626 members as of June 30, 2015 and holds the sabbath as one of the Pillars of Adventism. Seventh-day Adventism grew out of the Millerite movement in the 1840s, and a few of its founders (Cyrus Farnsworth, Frederick Wheeler, a Methodist minister and Joseph Bates, a sea captain) were convinced in 1844-1845 of the importance of Sabbatarianism under the influence of Rachel Oakes Preston, a young Seventh Day Baptist laywoman living in Washington, New Hampshire and a published article in early 1845 on the topic (Hope of Israel) by Thomas M. Preble, pastor of the Free Will Baptist congregation in Nashua, New Hampshire.
Seventh-day Adventists observe the sabbath from Friday evening to Saturday evening. In places where the sun does not appear or does not set for several months, such as northern Scandinavia, the tendency is to regard an arbitrary time such as 6 p.m. as "sunset". During the sabbath, Adventists avoid secular work and business, although medical relief and humanitarian work is accepted. Though there are cultural variations, most Adventists also avoid activities such as shopping, sport, and certain forms of entertainment. Adventists typically gather for church services on Saturday morning. Some also gather on Friday evening to welcome in the sabbath hours (sometimes called "vespers" or "opening Sabbath"), and some similarly gather at "closing Sabbath".
Traditionally, Seventh-day Adventists hold that the Ten Commandments (including the fourth commandment concerning the sabbath) are part of the moral law of God, not abrogated by the teachings of Jesus Christ, which apply equally to Christians. This was a common Christian understanding before the Sabbatarian controversy led Sunday-keepers to adopt a more radical antinomian position. Adventists have traditionally distinguished between "moral law" and "ceremonial law", arguing that moral law continues to bind Christians, while events predicted by the ceremonial law were fulfilled by Christ's death on the cross.
For further information please see the following article(s):
There are probably 4 components that are combined to build the case.
Firstly that the Sabbath is pre-exilic and is found in creation. Essentially baked into the fabric of our week.
Second, it is directly spoken by God in the 10 commandments. Linked to creation and is the only command to do that. Suggesting that it has a beginning outside of the Israelite covenant on Mount Sinai.
Third, The Sabbath is never condemned by Jesus. The strict expectations of the Jewish leaders were condemned, but the sabbath never was. Jesus even validated the sabbath.
The Sabbath was made for man, not man for the Sabbath. - Mark 2:27
Finally, the Sabbath forms part of the Advent message. When Adventist Interpret Revelation they see a prophecy in which those that are sealed have the testimony of Christ and keep the commands of God. When looking at the three angels message of revelation 14:6-12 You see creation brought into the first angel's message and the endurance of the saints at the end of that passage.