Tafsir of Az-Zukhruf 43:31

"And they said, 'Why was this Quran not sent down upon a man from the two towns?'"

Meaning: from one of the two towns, Makkah and Ta’if, or from their men. Thus, the [preposition] min (from) denotes origination or partition. It has been recited as rajulin with the jim quiescent [in some readings].

"Great"

In terms of status and wealth. Ibn Abbas said: The one from Makkah was al-Walid ibn al-Mughirah al-Makhzumi, and the one from Ta'if was Habib ibn ‘Amr ibn ‘Umayr ath-Thaqafi. Mujahid said: ‘Utbah ibn Rabi’ah and Kinanah ibn ‘Abd Yalil. Qatadah said: al-Walid ibn al-Mughirah and ‘Urwah ibn Mas’ud ath-Thaqafi.

Al-Walid ibn al-Mughirah used to be called "the Basil of Quraysh," and he would say: "If what Muhammad—may Allah bless him and grant him peace—says were true, it would have been revealed to me or to Ibn Mas’ud," meaning ‘Urwah ibn Mas’ud, who was known by that [aforementioned] kunya.

This is another dimension of their denial of Prophethood; they first denied that a human could be [a Messenger]. Then, when they were rebuked through the repetition of arguments and were left with no way to conceive of that [denial] gaining traction, they approached their denial from another angle, dictating to Allah—Glory be to Him—that the Messenger must be one of these two men.

Their saying "this Quran" is a mention of it by way of belittlement, for they did not make this statement in submission, but in denial. It is as if it were said: "This falsehood he claims, if it were true, would be appropriate only for a great man from the two towns." This is from their ignorance of the fact that the rank of Prophethood requires greatness of soul through the abandonment of base vices and the adornment of holy perfections and virtues, not through ornamentation with worldly vanities.