AN NAHL — Ayat 103
وَلَقَدْ نَعْلَمُ أَنَّهُمْ يَقُولُونَ إِنَّمَا يُعَلِّمُهُ بَشَرٌ لِّسَانُ الَّذِي يُلْحِدُونَ إِلَيْهِ أَعْجَمِيٌّ وَهَـذَا لِسَانٌ عَرَبِيٌّ مُّبِينٌ
And We certainly know that they say, "It is only a human being who teaches the Prophet." The tongue of the one they refer to is foreign, and this Qur'an is [in] a clear Arabic language.
Tafsir Ibnu Katsir
وَلَقَدْ نَعْلَمُ أَنَّهُمْ يَقُولُونَ إِنَّمَا يُعَلِّمُهُ بَشَرٌ لِّسَانُ الَّذِى يُلْحِدُونَ إِلَيْهِ أَعْجَمِىٌّ وَهَـذَا لِسَانٌ عَرَبِىٌّ مُّبِينٌ
103. And indeed We know that they (polytheists and pagans) say: â€It is only a human being who teaches him.'' The tongue of the man they refer to is foreign, while this (the Qur'an) is (in) a clear Arabic tongue. Allah tells us about the idolators' lies, allegations, and slander when they claimed that this Qur'an which Muhammad had recited for them, was actually taught to him by a human. They referred to a foreign (i.e., non-Arab) man who lived among them as the servant of some of the clans of Quraysh and who used to sell goods by As-Safa. Maybe the Messenger of Allah used to sit with him sometimes and talk to him a little, but he was a foreigner who did not know much Arabic, only enough simple phrases to answer questions when he had to. So in refutation of their claims of fabrication, Allah said: