The point is that His words,
“Sent down from your Lord,”
make clear that it was sent down from Allah, not from any created being. Hence the early generations said, “From Him it originated,” meaning that He is the One who spoke it; it did not originate with anyone else, as those who hold it to be created claim.
Another implication of His words, “Sent down from your Lord,” is that they invalidate the view that it emanated into the soul of the Prophet, may Allah bless him and grant him peace, from the Active Intellect or some other source, as various groups among the philosophers and the Sabians maintain. This view is even greater in unbelief and misguidance than the preceding one.
Another implication is that this verse also invalidates the view that the Arabic Quran was not sent down from Allah but was instead created—either within Gabriel, within Muhammad, or within some other body. This is maintained by the Kullābiyyah and Ashʿariyyah who say that the Arabic Quran is not Allah’s speech; rather, His speech is only the meaning subsisting in His essence, and the Arabic Quran was created to signify that meaning.
On this account, it was either created in some physical body—air or something else—or Gabriel was inspired with it and expressed it as the Arabic Quran, or Muhammad was inspired with it and expressed it as the Arabic Quran, or Gabriel took it from the Preserved Tablet or elsewhere. These previously mentioned views are thus ramifications of this position, for this Arabic Quran must have had a speaker who first spoke it before it reached us.