Why are there 66 Chapters in the Book of Isaiah?
The answer to this question is the same for every book of the Bible (except the number of chapters will differ). The length of any book is precisely what the human and divine authors intended (see John 20:30-31). This is why we are warned about adding to our taking from the Scriptures (Revelation 21:18-19; see also Deuteronomy 4:1-2). As
I’m sure you know, chapter and verse indicators are not a part of the original text, but have been added at a later time for the reader's benefit. There are times when we would disagree about chapter and verse divisions as we have them.
In short, Isaiah has 66 chapters because that is the way those in the past divided the book (divisions, I might add, that are not inspired or inerrant). While some may press for added significance to such divisions (e.g., There are 66 books in the Bible — Isaiah is a miniature of the Bible), these conclusions are inferential, and not clearly stated in Scripture.
The following is a portion from the International Standard Bible Encyclopedia, under “The Bible”:
1. Chapters and Verses: Already in pre-Talmudic times, for purposes of reading in the synagogues, the Jews had larger divisions of the law into sections called Para-shahs, and of the prophets into similar sections called HaphTarahs. They had also smaller divisions into Pecuqim, corresponding nearly with our verses. The division into chapters is much later (13th century). It is ascribed to Cardinal Hugo de St Caro (died 1248); by others to Stephen Langton, archbishop of Canterbury (died 1227). It was adopted into the Vulgate, and from this was transferred by R. Nathan (circa 1440) to the Hebrew Bible (Bleek, Keil). Verses are marked in the Vulgate (Jerome's Latin Bible, 390-405 A.D.) as early as 1558. They first appear in the New Testament in Robert Stephens' edition of the Greek Testament in 1551. Henry Stephens, Robert's son, reports that they were devised by his father during a journey on horseback from Paris to Lyons.
Related Topics: Bibliology (The Written Word)