In the prophetic Book of Thel, and in his other prophetic books, Blake uses the fourteener: lines that are 14 syllables long, with varying metrical stresses. According to The Princeton Encyclopedia of Poetry and Poetics, Blake used the fourteener “probably in imitation of the biblical style from various English translations” (Greene, Roland, et al. The Princeton Encyclopedia of Poetry and Poetics. 4th ed., Princeton University Press, 2012, p. 504). These long lines are unrhymed and generally fill most of the horizontal space in Blake’s etched plates, as well as a modern standard book page.

Blake’s fourteener lines are organized in stanzas of varying lengths. Most short stanzas—consisting of one to three lines—contain action and/or dialogue tags (clarify who is talking and/or what they are doing). On the other hand, long stanzas—five to 10 lines—contain dialogue and descriptions of locations: the vales of Har and the land of the dead.

The preface, Thel’s Motto, contains four lines that alternate in length between 10 and seven syllables. The lines that have 10 syllables do not rhyme; the seven-syllable lines rhyme. This preface comes before the cover illustration. The Book of Thel is an illuminated book, meaning that the text is meant to be read alongside Blake’s etched illustrations.