The actual content of John’s book begins from chapter 1:9. As I have already indicated somewhere, the prologue is a written work of someone other than John the Revelator. A step by step commentary reveals the circumstances that led him to Patmos and eventually the reception of the vision.
1:9 I John—The first of three of its appearances (1:9; 21: 2; 22: 8). This is how John took a transition to tell everything about the vision. He writes as a first-hand witness of the vision (1: 2). John introduces himself as a brother. Whether he was personally known by his recipients or not, he identifies himself with the community of believers as a fellow in Christ. Companion in tribulation—The Greek word translated companion is συνκοινωνὸς (sunkoinōnos), from sun and koinōnos (co-partner). The New American Standard Bible translates it as “fellow partaker.” Tribulation comes to all without favoritism. We know from this phrase that the Christians were already under the threat of the Roman regime. Patient endurance—Persevering or longsuffering. The word becomes the identification of the saints (13: 10; 14: 12) and no wonder John uses for himself as well. See Acts 14: 22. Was on the island of Patmos—Is John writing a past experience at Patmos or writing from Patmos? He speaks from the past ἐγενόμην (aorist indicative “I was,” meaning the immediate circumstance has changed). The same word is used to describe the death of Christ in 1: 18, “I was dead.” It’s probable that the vision was given at Patmos but it was written after his release. Tradition suggests that John did not die on Patmos. Clement of Alexandria (A.D. 150 – 215) says, “For when, on the tyrant’s death, he returned to Ephesus from the Isle of Patmos” (Clement of Alexandria. “Who Is The Rich Man?” XLII, Ante-Nicene Fathers. II, p. 603). The dating of the book to the late first century may suggest too well that it was written at the latter part of Domitian’s reign or after his death around A. D. 96. John MacArthur comes to a similar conclusion:
“Revelation was written in the last decade of the first century (ca. A.D. 94-96), near the end of Emperor Domitian’s reign (A.D. 81-96). Although some date it during Nero’s reign (A.D. 54-68), their arguments are unconvincing and conflict with the view of the early church. Writing in the second century, Irenaeus declared that Revelation had been written toward the end of Domitian’s reign. Later writers, such as Clement of Alexandria, Origen, Victorinus (who wrote one of the earliest commentaries on Revelation), Eusebius and Jerome affirm the Domitian date.” (MacArthur, John. The Macarthur Bible Handbook. Nashville, Tenn: Thomas Nelson Publishers, 2003).
1:10 I was in the spirit on the Lord’s day—The vision is not written and handed to John. He was under the influence of the Spirit to behold spiritual realities (Num 12: 6). The Lord’s Day—The expression κυριακῇ ἡμέρᾳ appears only once in the entire Bible at 1: 10. Three possible theories exist in the meaning of the phrase. First, as the justification for the weekly Sunday day of worship. Proponents of this theory rely on early Church fathers’ usage of the term. Ignatius of Antioch (35-108) who lived during the time of writing of the book of Revelation used the terms Sabbath and Lord’s Day separately. He seemed to deploy Christians to live “in the observance of the Lord’s Day” (Epistle to the Magnesians, 9). For further commentary on this theory, see Jamieson, R., Fausset, A. R., & Brown, D. (1997). Commentary Critical and Explanatory on the Whole Bible (Vol. 2, p. 552). The second theory sees the day as the great day of the Lord (Judgment Day). It connects John’s immediate scene in the vision to the apocalyptic end-time in the book. Others refer to the Lord’s Day in the Old Testament. From E. W. Bullinger’s Commentary on Revelation:
“For what is the “DAY of the Lord” or “the LORD’S day”? The first occurrence of the expression (which is the key to its meaning) is in Isaiah 2:11.8 It is the day when “the lofty looks of man shall be humbled, and the haughtiness of men shall be bowed down, and the Lord alone shall be exalted.
That is the one great object of all the future events, seen by John in vision, and recorded for us in the Apocalypse.”
Lastly, other commentators refer to the weekly Sabbath of the Ten Commandments. The allusion is derived from Jesus’ statement in Mark 2: 28, “Lord of the Sabbath.” Adventist Sabbath School, Jan.7, 2019 states:
Revelation 1:10 clearly suggests that the apostle John received the vision on the seventh-day Sabbath. Although looking with anticipation toward future events, even to the second coming of Christ (compare with Rev. 1:7), which is called “the day of the LORD” (Isa. 13:6-13; 2 Pet. 3:10), John was talking about the time at which he, himself, had the vision of these future events, and that was on the Sabbath, the “Lord’s day”.
The context we find ourselves in 1: 10 is an actual day in the time of the vision. Since John described what he heard and saw at first, it wouldn’t be convincing to easily conclude that he was in a vision of the great day of the Lord. Neither is there any strong evidence in the New Testament that the Sabbath nor the first day of the week was known as the Lord’s day. Both days are called by their respective names, Sabbath or the first day of the week in the New Testament. Jesus as “the Lord of the Sabbath” was in reference to the Old Testament “I am the Lord thy God,” a statement often associated with the Sabbath (Ex 20: 8-11; 31: 13; Lev 19: 3; 19: 30; 26: 2; Is 58: 13-14; Ez 20: 12; 20: 20). “The Lord’s day,” from the original Greek roots may also mean “the day that belongs to the Lord,” or the day dedicated to the Lord. Although Church tradition may support the resurrection day (first day of the Week), the Lord’s day is not a substitute of the Sabbath of the Ten Commandments. For an in-depth study of the subject, see From Sabbath to Lord’s Day: A Biblical, Historical and Theological Investigation by D. A. Carson (Ed), and Samuele Bacchiocchi Sabbath Studies Collection (3 vols.) by Samuel Bacchiocchi. A great voice as of a trumpet—John’s first encounter in the vision is a call; obviously, a summon to the task.