Surah Al-Muzzammil, ayah 5

73:5

إِنَّا سَنُلۡقِي عَلَيۡكَ قَوۡلٗا ثَقِيلًا ٥

Innā sanulqī 'alayka qawlan thaqīlā

Indeed, We will cast upon you a heavy word.1779

Footnotes

1779 i.e., the revelation, which when descending on the Prophet (ﷺ) bore down upon him with a great weight. Another meaning is "important ordinances."