فَإِذَا جَآءَتِ ٱلطَّآمَّةُ ٱلْكُبْرَىٰ
Fa-izaa jaaa'atit taaam matul kubraa.
But when the great overwhelming calamity comes,
Al-ṭāmma pictures water rising until it covers whatever lies beneath it, and kubrā ranks this flood above every other disaster. The surah reaches it straight from a list of gifts that ends on your livestock, and the next surah, ʿAbasa, turns on the same words at the same point, naming the day there as the blast that deafens. Here the last day is something that submerges, and there something that strikes the ear.