Ash-Shu'araa • AR-TAFSIR-IBN-KATHIR
﴿ فَيَأْتِيَهُم بَغْتَةًۭ وَهُمْ لَا يَشْعُرُونَ ﴾
“that will come upon them [on resurrection,] all of a sudden, without their being aware [of its approach];”
"فيأتيهم بغتة" أي عذاب الله بغتة.