فَيَومَئِذٍ وَقَعَتِ الواقِعَةُ
Then, on that day, will the imminent [hour] befall.
EXEGESIS
On that day (yawmaʾidhin) is a continuation of the preceding verses and is added to emphasise its significance. It is also an extremely common expression in the Quran used to describe events in the hereafter.
Waqaʿa (befall) is literally to fall, drop, or tumble; it is also, and especially in the context of this verse, to come to pass, occur, take place, befall. From this same verb is also the noun al-wāqiʿah, translated here as the imminent [hour]. Al-wāqiʿah, however, is simply and literally the incident, the event, the occurrence; but it is understood here as the imminent [hour] because of how the term is used in its definite form in the Quran, such as in the opening verses of chapter 56, Sūrat al-Wāqiʿah (see also the Exegesis of 56:1).
When the Quran does refer to this apocalyptic event literally as ‘the hour’, it usually uses the term al-sāʿah and it does this numerous times (12:107, 15:85, 16:77, 18:21, 20:15, 21:49, 22:7, 30:12, 30:14, 30:55, 31:34, 33:63, 40:46, 40:59, 41:47, 42:17, 43:85, 45:27, 45:32, 47:18, 54:1, 79:42, etc.).
Will the imminent [hour] befall means the end of the world as we know it, leading to the resurrection and judgement being established. The imminent [hour] is therefore the whole event. It sits at the crossroads of the two trumpet blows (verse 13) such that all verses in this surah before this verse describe the world’s destruction, and the verses after this describe the Day of Resurrection and Accounting.