Quran 26:27 from Surah Ash-Shu'araa on Divine Marvels.
قَالَ إِنَّ رَسُولَكُمُ ٱلَّذِيٓ أُرۡسِلَ إِلَيۡكُمۡ لَمَجۡنُونٞ
English translation: He said Indeed your Messenger who has been sent to you (is) surely mad
Transliteration: qala inna rasulakumu alladhi ur'sila ilaykum lamajnunun