These verses serve as the ultimate "Chain of Authority," where the Quran attempts to validate its message by linking it directly to the most prominent figures of the Judeo-Christian tradition.
For the critic, this is the "Consistency Clause"—if the inspiration is the same, the message cannot contradict itself.
Surah 4:163-164:
We have sent thee inspiration, as We sent it to Noah and the Messengers after him: we sent inspiration to Abraham, Isma'il, Isaac, Jacob and the Tribes, to Jesus, Job, Jonah, Aaron, and solomon, and to David We gave the Psalms.Of some messengers We have already told thee the story; of others We have not; - and to Moses Allah spoke direct.
The verse begins with Inna aw hayna ilayka kama aw hayna... ("Indeed, We have revealed to you as We revealed to...").
The word kama implies a qualitative and thematic identity. If the revelation to David (the Psalms) and the revelation to the "Descendants" (the New Testament writers) teaches that God is a Father and the Messiah is His Son who provides atonement, then the Quranic revelation must match that theme to be truthful.
If the Quran contradicts the Zabur or the Gospel, it fails its own "Kama" test.
By specifically mentioning David and the Psalms, the Quran anchors itself to a text that was widely available in the 7th century.
The Psalms are filled with "Son" terminology (Psalm 2) and Messianic suffering (Psalm 22).
If Allah gave David the Psalms, and the Psalms point to a divine/suffering Messiah, then the Quran cannot claim to be from the same Source while denying those very attributes. It turns the Zabur into a hostile witness against the Quranic narrative.
The mention of God speaking "directly" to Moses (Takliman) in 4:164 is used to affirm the highest level of textual authority for the Torah.
If the Torah is the result of direct speech from God, its preservation becomes a matter of divine integrity. By highlighting Moses’ unique status, the Quran makes the Torah the "Master Standard." If the Torah's legal and sacrificial system (the "Blood Atonement") is the "Direct Speech" of God, the Quranic dismissal of that system creates a theological rupture that the "Chain of Prophets" cannot mend.
Surah 4:163-164 creates a "Prophetic Contract." By claiming to be the latest link in a chain that includes the Zabur and the Torah, the Quran submits itself to the testimony of those earlier books.
The question is simple: Does the "Arabic Quran" harmonize with the "Direct Speech" given to Moses and the "Songs" given to David? If it doesn't, the claim of being revealed "as they were revealed" is historically and theologically unsustainable.