And, indeed, full well do We know that they say, "It is but a human being that imparts [all] this to him! -[notwithstanding that] the tongue of him to whom they so maliciously point is wholly outlandish, whereas this is Arabic speech, clear [in itself] and clearly showing the truth [of its source].
And We do know what they say, thus: "He -Muhammad- is being taught by a man who dictates to him the words he expresses to the people". But the man they refer to is foreign while the Quran is being revealed in plain Arabic literary form.
We know that they say a mere mortal has taught it (the Quran) to him (Muhammad). The language of the person whom they think has taught it to him is not Arabic. This (the Quran) is in illustrious Arabic.
We also know that they (the disbelievers) say, "It is a man who teaches him (the Prophet)." His (the Prophet’s) tongue, that they (wickedly) point to be notably different, whereas this is Arabic, pure and clear.
And indeed, We know that they (the disbelievers and the polytheists) say: ‘It is but a human being who teaches him this (Qur’an).’ But the person they point to, turning the matter away from the truth, is the one whose language is non-Arabic and this Qur’an is (in) a clear and unambiguous Arabic language.
Dr. Kamal Omar
And surely, without doubt We know that they say: “Surely that who teaches him is a human being." The (mother) tongue of him they refer to is Aajamiyyun (non-Arabic, not fully capable of harbouring and explaining the Divine Message), while this (i.e., the original Text of Al-Kitab) is manifestly evident, (most classical) Arabic language.
Surely We know well that they say about you: "It is only a human being who teaches him," (notwithstanding) that he whom they maliciously hint at is of foreign tongue, while this (Qur´an) is plain Arabic speech.
I am aware of what they say (in their gatherings) about you: “Such and such person is teaching him the subject matter of Qur’an (from the biblical sources.)” The funny thing is that the maternal language of this such and such person (that they are referring to) is not Arabic and that the Qur’an is presented in a perfect Arabic language.
And indeed We know that they say, "This Qur’an is being taught by some other man"; the one they refer to speaks a foreign language, whereas this is clear Arabic!
Hasan Al-Fatih Qaribullah
We know very well that they say: 'A mortal teaches him. ' The tongue of him at whom they hint is a nonArab; and this is a clear Arabic tongue.
And indeed We know that they say: Only a mortal teaches him. The tongue of him whom they hint at is foreign, and this is clear Arabic language.
Muhammad Ahmed - Samira
And We have known that they say: "But/indeed a human teaches/instructs him, (the) tongue/language/speech (of) those who deviate, insult and defame to Him, non-Arabic/Persian (tongue/language/speech), and this (is) an Arabic clear/evident tongue/language/speech.
And indeed WE know that they say that it is only a man who teaches him. But the tongue of him towards whom their minds is inclined in making this insinuation is foreign while this is Arabic tongue plain and clear.
And We know fully well what they say (by way of objection) that this (Qur'an) is (not revealed by God but it is) only what a human being instructs to him (- to Muhammad). But (strange it is) that the tongue of him to whom they (unjustly) allude (of making this insinuation) is foreign and wanting in clearness, whereas the language of this (Qur'an) is chaste Arabic, plain and clear.
And indeed We know that they (polytheists and pagans) say: "It is only a human being who teaches him (Muhammad SAW)." The tongue of the man they refer to is foreign, while this (the Quran) is a clear Arabic tongue.
We also know that they say, verily, a certain man teacheth him to compose the Koran. The tongue of the person unto whom they incline, is a foreign tongue; but this, wherein the Koran is written, is the perspicuous Arabic tongue.