al-Naḥl 16:103

Wa laqad naʿlamu annahum yaqūlūna innamā yuʿallimuhū bashar, lisānu'lladhī yulḥidūna ilayhi aʿjamiyyun wa hādhā lisānun ʿarabiyyun mubīn

"We know well that they say: 'A human being is teaching him.' The tongue of the one they hint at is foreign; and this is a clear Arabic tongue."

This verse was named at al-Zukhruf, 43/3, and it was recorded there: "At al-Naḥl 16/103 the word occurs as an answer to an objection: there aʿjamī is set as the opposite of ʿarabī." I rely on that treatment.

And the method of the answer must be recorded, and I give this as an observation: the verse refutes the claim not morally but linguistically. It does not say "such a thing cannot be"; it says "the tongue of the one you hint at is another tongue".

The answer, that is, is taken from inside the addressee's own claim.

يُلْحِدُونَ — root ل-ح-د: to swerve to one side, to bend aside. Laḥd — the niche cut into the side of a grave (the Turkish lahit comes from this); mulḥid — one who swerves from the straight. The root was treated at Fuṣṣilat, 41/40 (yulḥidūna fī āyātinā); I rely on that treatment.

And the use of the verb here is worth recording: yulḥidūna ilayhi — "they lean towards him", that is, they hint at him. The root's picture of "swerving to the side" produces the sense of "pointing indirectly".

أَعْجَمِىّ — root ع-ج-م: not to be clear in speech, to be unintelligible. Aʿjam — one who cannot state his meaning plainly; the word names not a people but a condition of intelligibility.

I record this as an observation about the language, and per the method (Method) I state it separately: the verse lays down no value-judgement about a language or a people. The contrast does not lie on the axis ʿarabī / aʿjamī but on the axis intelligible / unintelligible — indeed the verse adds the adjective mubīn (plain) to the word ʿarabī. The stress falls not on the name of the tongue but on its clarity.