وَقَالُوا۟ يَـٰٓأَيُّهَا ٱلَّذِى نُزِّلَ عَلَيْهِ ٱلذِّكْرُ إِنَّكَ لَمَجْنُونٌ
Wa qaaloo yaaa aiyuhal lazee nuzzila 'alaihiz Zikru innaka lamajnoon
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.