Following a rigorous list of eighteen prophets ranging from Abraham and Noah to Moses and Jesus, this verse acts as a divine "Certificate of Title," affirming that the Scripture, the authority, and the prophetic office were truly theirs.
Surah 6:89:
Those are the ones to whom We gave the Scripture and authority and prophethood. But if the disbelievers deny it, then We have entrusted it to a people who are not therein disbelievers."
The verse lists a diverse group of prophets (Noah, David, Jesus, etc.) and says God gave them "The Scripture" (singular).
This reinforces the Quranic view that the Torah, the Psalms, and the Gospel are not separate, competing messages, but are collectively "The Book."
If this collective "Book" was given to these prophets as a mark of their authority, it must be a consistent, non-contradictory body of work. For the investigator, this presents a challenge: if the Quran is the latest addition to this "Book," it must harmonize with the previous authors (like David and Jesus) listed in the preceding verses (6:83-86).
The second half of the verse provides a historical safeguard: "If the disbelievers deny it, then We have entrusted it to a people who are not therein disbelievers."
This is a direct blow to the theory of "Total Corruption." The Quran asserts that even if one group rejects the Scripture, God ensures it is entrusted (wakkalnā) to a people who believe in it.
In the 7th century, the "people" who were not disbelievers in the Torah and Gospel were the Jews and Christians. If God "entrusted" the Scripture to them, He would not allow them to successfully corrupt it into a lie, as that would mean God's "entrustment" had failed.
The prophets were given Al-Hukm (Authority/Judgment) alongside the Book. You cannot exercise divine authority or judgment with a corrupted or missing law.
By linking the Scripture to "Authority," the verse confirms that the books of these prophets remained the valid, authoritative standard for judgment. This aligns with the command in Surah 5:47 for Christians to "judge by" their Gospel—it is the Hukm given to them that they are required to uphold.
Surah 6:89 is a verse of continuity. It identifies the Bible not as a collection of human writings that were eventually "lost," but as the very "Scripture and Authority" given by God to His most prominent messengers.
By stating that this Scripture is "entrusted" to those who believe in it, the Quran provides a divine guarantee of its presence and validity.
The "Book" given to the eighteen prophets is the same "Book" the Quran claims to confirm; therefore, the testimony of those eighteen prophets remains the benchmark for all truth-claims that follow.
How does the command in the very next verse (Surah 6:90) for Muhammad to "follow their guidance" affect the argument that the Quran came to change the previous laws?