What is the justification for using the noble verse: "Indeed, it is the word of a noble messenger" to argue that the speech is attributed to the conveyor, even though it confirms that attributing the speech to the conveyor does not mean it is his own words?

The point of inference from the noble verse: (Indeed, it is the word of a noble Messenger) is that the Qur'an is the word of Allah Almighty, and it was attributed to the Messenger, peace and blessings be upon him, because he is the one who conveyed it. Ibn al-Jawzi mentioned that there are two opinions regarding who the Messenger refers to: Muhammad, peace and blessings be upon him (which is the opinion of the majority), or Jibreel. Ibn Qutaybah, Al-Qurtubi, and Ibn Kathir clarified that attributing the word to the Messenger is an attribution of conveyance, not an attribution of authorship. The Messenger conveys from the Sender, just as a statement is attributed to Imam Malik, and it is his statement about Allah.