Sūrat al-Wāqiʿah is the fifty-sixth chapter of the Quran and it was revealed in Mecca. It is apparently the forty-sixth chapter that was revealed, after Sūrat Ṭā Hā (20) and before Sūrat al-Shuʿarāʾ (26). It consists of ninety-six verses. Its name is obtained from the first verse, which talks about the certain and imminent event, al-wāqiʿah.
The verses of this surah are very coherent and they all follow the same theme: the description of the three main groups of people on the Day of Judgement. The chapter starts with introducing the setting of the Day of Judgement (verses 1-6), followed by a detailed description of the rewards and punishments of the three groups (verses 7-56). It then brings up a series of compelling arguments to which everyone can relate, in order to prove the inevitability of the afterlife (verses 57-74). The next set of verses (75-82) serves to prove the truth of the Quran, including its reports of the hereafter. Finally, the surah ends by noting how close and invincible death is, followed by a short summary of the descriptions of the rewards and punishments that await (verses 83-96).
Verse 79 of this surah is of special importance as it involves practical implications for how to approach the Quran in order to reach its reality. In addition to that, verses 57-74 are also very significant because they provide a very profound cosmology based on the unicity in actions (al-tawḥīd al-afʿālī).
[1] Tamhid, 1/136.