Commentaries:
All the inset chapters are introduced in a significant way: by an angel coming down from heaven or a spectacular and unusual vision of someone or something, such as a woman clothed with the sun, moon, and stars or a Beast rising up out of the ocean.
Chapter 11, however, does not begin this way because it is not the beginning of the inset. The inset actually begins in Revelation 10:1 where the spectacular vision occurs. Chapter 10 does not follow chapter 9 in time sequence anymore than the material in chapter 11 does. Chapter 11 merely continues the vision begun in chapter 10.
John W. Ritenbaugh
Revelation 10 and the Laodicean Church
Revelation 11 is inset material. The only possible period of time when the Two Witnesses could testify is during the three and a half years that precede Christ's return—the time of the Tribulation and the Day of the Lord.
Most of this period of time has already been covered by chapters 6 (the fifth and sixth seals) and 8-9 (the trumpet plagues). Chapter 11 clarifies what has already occurred in the narrative, answering how people can possibly be converted during the Tribulation and the Day of the Lord. The answer is that they are hearing a message thundered by the Two Witnesses! Revelation 7:9-17 suggests that by their preaching, an innumerable multitude will be converted.
The information is given in a digression—an inset chapter— from the main story flow. Inset chapters clarify what is happening within the time sequence.
John W. Ritenbaugh
Revelation 10 and the Laodicean Church
Other Forerunner Commentary entries containing Revelation 11:13:
Revelation 5:1-4
Revelation 6:15-17
Revelation 11:14