 إِذَا وَقَعَتِ ٱلْوَاقِعَةُ

Allah gives 20 different names for the Day of Judgement in the Quran! About this, Imam al-Qurtubi said:
'Anything that is great has a many descriptions and names; this was part of the oral tradition of the Arabs. Consider how important the sword is to them, and how beneficial they would consider it to be in their lives. They have five hundred names for it! Because of how important the Day of Resurrection is, and how plentiful its terrors are, Allah, the Exalted, called it by many names in His scripture, and mentioned many descriptions for it' (Source: at-Tadhkirah). 

Allah begins surah al-Waqi’ah by describing the Day of Resurrection as:

    إِذَا وَقَعَتِ الْوَاقِعَةُ * لَيْسَ لِوَقْعَتِهَا كَاذِبَةٌ * خَافِضَةٌ رَّافِعَةٌ

    When the Event befalls. * And there can be no denying of its befalling. * It will bring down and raise up. [56:1-3]

    Commenting on this, Imam al-Baghawi wrote:

     تخفض أقواما إلى النار ، وترفع آخرين إلى الجنة . وقال عطاء عن ابن عباس : تخفض أقواما كانوا في الدنيا مرتفعين ، وترفع أقواما كانوا في الدنيا مستضعفين

    It will bring some people down to the hell-fire and raise others up to al-Jannah.

    ‘Ataa’ relayed that ibn ‘Abbaas said: it will lower some people who has been elevated in this life, and it will raise some people who had been powerless in this life.

    [Tafsir al-Baghawi 8/7]

♦ Mentioning the Day of Judgement and Death Together

    In part of a discussion regarding surah al-Qamar, sheikh al-Islam ibn Taymiyah highlighted the following stylistic feature of the Qur’an:

     والله تعالى في كتابه يجمع بين ذكر القيامة الكبرى والصغرى كما في سورة الواقعة ذكر في أولها القيامة الكبرى وفي آخرها القيامة الصغرى وذلك كثير في سور القرآن مثل سورة ق وسورة القيامة وسورة التكاثر وسورة الفجر وغير ذلك

    Throughout His Book, Allah has often mentioned both the Day of Judgement and death together. Take, for example, surah al-Waqi’ah [56] – He mentioned the Day of Judgement in the beginning of the surah and death at the end.

    This [i.e. jointly mentioning the Day of Judgement and death] can be found in many surahs throughout the Qur’an, such as surah Qaf [50], surah al-Qiyamah [75], surah al-Takathur [102], surah al-Fajr [89], and others.

    [al-Jawab al-Saheeh 1/424]