The biblical text itself explicitly claims that much of it is composed of copies, abridgments, or expansions of earlier documents. This is clear in Jeremiah 36, where Jeremiah asks Baruch, his scribe, to “write on a scroll at the dictation of Jeremiah all the words of YHWH that he had spoken to him” (Jer. 36:4). This scroll is burnt by king Zedekiah (Jer. 36:23), after which Jeremiah dictates the same prophecies to Baruch again, with “many similar words were added to” the words of the original scroll. In other words, there were at least two edition of Jeremiah within his own lifetime—a first scroll burned by Zedekiah, and a second scroll to which additional prophecies were added.
The Bible mentions numerous books quoted or abridged in the composition of the Bible. These “lost books” books include:
• Book of Jasher (Joshua 10:13; 2 Samuel 1:18)
• Book of the Wars of the Lord (Numbers 21:14)
• Chronicles of the Kings of Israel (1 Kings 14:19, 14:29, 16:20; 2 Chr. 33:18)
• Chronicles of the Kings of Judah (1 Kings 14:19, 14:29)
• Book of Shemaiah the Prophet (2 Chr. 9:29, 12:15, 13:22)
• Book of Iddo the Seer (2 Chr. 9:29, 12:15, 13:22)
• Acts of Solomon (1 Kings 11:41)
• Chronicles of King David (1 Chr. 27:24)
• Book of Nathan the Prophet (1 Chr. 29:29; 2 Chr. 9:29)
• Book of Gad the Seer (1 Chr. 29:29)
• Book of Jehu (2 Chr. 20:34)
• Sayings of the Seers (2 Chr. 33:19)
• Laments for Josiah (2 Chr. 35:25)
None of these books have survived from antiquity. There were undoubtedly many more similar texts that were used by biblical authors, but were never named. In other words, the Bible as we have it explicitly states that at least large segments of it were composed in part by quoting, abridging, or summarizing other Israelite texts which are now lost. Note, that this is equally true of all other ancient cultures. The vast majority of ancient books from all world civilizations are irretrievably lost. The great library of Alexandria, for example, is said to have contained 500,000 scrolls. Only the equivalent of a few thousand of these scrolls have survived.