In studies on the composition of prophetic literature, the larger textual layers reinterpreting earlier texts, the so-called Fortschreibungen, received much attention. It is well-known that beside these larger literary elaborations prophetic books also contain shorter explanatory interpolations, often called glosses, which intend to clarify a particular imagery of the prophecy (e.g., Isa 9:14). A systematic reading of these short annotations has been neglected, however, in studying the formation of prophetic books. The present article reconsiders the Isaiah-Memoir from this perspective. It identifies editorial interpolations in three distinct pericopes, Isa 8:2, 8:6-7a and 8:23b. It is argued here that the identification of such explanatory additions is the key to understanding notorious textual complexities. Moreover, it points out that these interpolations tend to expose recognisable patterns and common hermeneutical principles. Unlike Fortschreibungen, however, these interpolations are not concerned with the reapplication of the prophecy to the era of the editor, but they intend to guide the reader in understanding the prophecies in their original historical setting.
For the first option see GrayIsaiah pp. 136-37; for the second see J. Barthel: Prophetenwort und Geschichte. Die Jesajaüberlieferung in Jes 6-8 und 28-31 (FAT 19; Tübingen 1997) pp. 131-132; W. A. M. Beuken Jesaja 1-12 (HThKAT; Freiburg 2003) pp. 189-90; H. G. M. Williamson “Poetic Vision in Isaiah 7:18-25” in A. J. Everson and H. C. P. Kim (eds) The Desert Will Bloom. Poetic Visions in Isaiah (Atlanta 2009) pp. 77 note 1. Duhm Jesaia p. 76 argues that the role of the later v. 17 was to connect two already existing pericopes vv. 10-16 with vv. 18-25. This view however—as Gray Isaiah p. 136 well noted— raises serious problems.
H. Klein“Freude an Rezin. Ein Versuch, mit dem Text Jes. viii 6 ohne Konjektur auszukommen”VT30 (1980) pp. 231-33; D. Barthélemy Critique textuelle de l’Ancien Testament (OBO 50/2; Fribourg 1986) p. 50; Barthel Prophetenwort pp. 200-202; M. A. Sweeney “ûmĕśôś in Isaiah 8:6” in Form and Intertextuality in Prophetic and Apocalyptic Literature (FAT 45; Tübingen 2005) p. 41; Beuken Jesaja p. 213.
E.g. GrayIsaiah p. 147; Wildberger Jesaja p. 322; Kaiser Jesaja p. 181; Sweeney Isaiah p. 171. As scholars usually note this interpolation disturbs the fluent connection between the metaphoric language of v. 7a and v. 7b.