Tafsir Ibn Kathir (abridged)
Explaining the Day of Decision and what occurs during it
Allah says about the Day of Decision -- and it is the Day of Judgement -- that it is at a fixed time, with a set appointment. Its time cannot be added to or decreased. No one knows its exact time except Allah. This is as Allah says,
وَمَا نُؤَخِّرُهُ إِلاَّ لاًّجَلٍ مَّعْدُودٍ
(And We delay it only for a term fixed.) (11:104)
يَوْمَ يُنفَخُ فِى الصُّورِ فَتَأْتُونَ أَفْوَاجاً
(The Day when the Trumpet will be blown, and you shall come forth in crowds.) Mujahid said, "Groups after groups." Ibn Jarir said, "This means that each nation will come with its Messenger. It is similar to Allah's statement,
Continue reading the tafsir of ayahs 17–30