The Book of Isaiah is the first of the Latter Prophets in the Hebrew Bible and the first of the Major Prophets in the Christian Old Testament. It is identified by a superscription as the words of the 8th-century BCE prophet Isaiah ben Amoz, but there is evidence that much of it was composed during the Babylonian captivity and later. Johann Christoph Döderlein suggested in 1775 that the book contained the works of two prophets separated by more than a century, and Bernhard Duhm originated the view, held as a consensus through most of the 20th century, that the book comprises three separate collections of oracles: Proto-Isaiah, containing the words of the 8th-century BC prophet Isaiah; Deutero-Isaiah, or "the Book of Consolation",, the work of an anonymous 6th-century BCE author writing during the Exile; and Trito-Isaiah, composed after the return from Exile. Isaiah 1–33 promises judgment and restoration for Judah, Jerusalem and the nations, and chapters 34–66 presume that judgment has been pronounced and restoration follows soon. While few scholars today attribute the entire book, or even most of it, to one person, the book's essential unity has become a focus in more recent research.

The Hebrew Bible or Tanakh, also known in Hebrew as Miqra, is the canonical collection of Hebrew scriptures, comprising the Torah, the Nevi'im, and the Ketuvim. Different branches of Judaism and Samaritanism have maintained different versions of the canon, including the 3rd-century BCE Septuagint text used in Second Temple Judaism, the Syriac Peshitta, the Samaritan Pentateuch, the Dead Sea Scrolls, and most recently the 10th-century medieval Masoretic Text compiled by the Masoretes, currently used in Rabbinic Judaism. The terms "Hebrew Bible" or "Hebrew Canon" are frequently confused with the Masoretic Text; however, this is a medieval version and one of several texts considered authoritative by different types of Judaism throughout history. The current edition of the Masoretic Text is mostly in Biblical Hebrew, with a few passages in Biblical Aramaic.