I's like to add that the New Testament writers were referring to the Scriptures that they had (and for a long time had) written in a scroll like the one Jesus read from - the book of Isaiah:

"The Bible that existed during the time of Jesus was a collection of writings that included the Torah, Nevi'im, and Ketuvim, which is known as the Tanakh:

Torah: The first five books of the Bible, also known as Genesis, Leviticus, Exodus, Numbers, and Deuteronomy

Nevi'im: The Prophets

Ketuvim: A looser group of writings that included Psalms, Proverbs, Daniel, Ruth, Esther, First and Second Chronicles, Ezra, and Nehemiah" - Google Search, AI Overview