وَقَالُوا۟ يَـٰٓأَيُّهَا ٱلَّذِى نُزِّلَ عَلَيْهِ ٱلذِّكْرُ إِنَّكَ لَمَجْنُونٌ
Wa qaaloo yaaa aiyuhal lazee nuzzila 'alaihiz Zikru innaka lamajnoon
They say, ‘Receiver of this Quran! You are definitely mad.
And they say, "You upon whom the reminder has been sent down — you are surely mad.
The taunt is built on a vocative that repeats the claim it means to reject: the man is addressed as the one upon whom the reminder was sent down, and no name is used at all. Majnun charges him with being jinn-touched, so the accusation concedes that something beyond him is speaking through him and quarrels only with what that something is.