Isaiah 42 is the forty-second chapter of the Book of Isaiah in both the Hebrew Bible and the Old Testament of the Christian Bible. This book contains the prophecies attributed to the prophet Isaiah, and is a part of the Books of the Prophets. Chapters 40-55 are known as "Deutero-Isaiah" and date from the time of the Israelites' exile in Babylon. This chapter contains a poem known as the first of the "Servant songs" about the servant, whom Jewish tradition holds that Isaiah identifies as either the Israelites themselves or Cyrus.

Isaiah 66 is the sixty-sixth and final chapter of the Book of Isaiah in the Hebrew Bible or the Old Testament of the Christian Bible. This book contains the prophecies attributed to the prophet Isaiah, and is one of the Books of the Prophets. Chapters 56–66 are often referred to as Trito-Isaiah. This chapter contains an oracle delivered after the temple in Jerusalem had been re-built following the Jewish peoples' return from exile, and warns against "an unduly materialistic" approach to the worship of God.