Complex sentence: Textual evidence indicates that the text for the festivals comes from another work and was incorporated into the Temple Scroll, which lists festivals that should be celebrated throughout the year, and many of the festivals are mentioned in the Bible and some festivals are unique.
Split into simpler sentences: Textual evidence indicates that the text for the festivals comes from another work and was incorporated into the Temple Scroll, and the Temple Scroll provides a list of the festivals that should be celebrated throughout the year. Many of the festivals are mentioned in the Bible, but some festivals are unique.