Quran 73:5 from Surah Al-Muzzammil on Divine Marvels.
إِنَّا سَنُلۡقِي عَلَيۡكَ قَوۡلٗا ثَقِيلًا
English translation: Indeed We will cast upon you a Word heavy
Transliteration: inna sanul'qi alayka qawlan thaqilan