Allah commands His servants to have Taqwa of Him, He informs them of the terrors of the Day of Resurrection which will come to them with its earthquakes and other horrors, as He says:

﴿إِذَا زُلْزِلَتِ الاٌّرْضُ زِلْزَالَهَا - وَأَخْرَجَتِ الأَرْضُ أَثْقَالَهَا ﴾

(When the earth is shaken with its (final) earthquake. And when the earth throws out its burdens.) ﴿99:1-2﴾

﴿وَحُمِلَتِ الاٌّرْضُ وَالْجِبَالُ فَدُكَّتَا دَكَّةً وَحِدَةً - فَيَوْمَئِذٍ وَقَعَتِ الْوَاقِعَةُ ﴾

(And the earth and the mountains shall be removed from their places, and crushed with a single crushing. Then on that Day shall the (Great) Event befall.) ﴿69:14-15﴾ And;

﴿إِذَا رُجَّتِ الاٌّرْضُ رَجّاً - وَبُسَّتِ الْجِبَالُ بَسّاً ﴾

(When the earth will be shaken with a terrible shake. And the mountains will be powdered to dust.) ﴿56:4-5﴾ It was said that this earthquake will come at the end of the life span of this world, at the outset of the Hour. Ibn Jarir recorded that `Alqamah commented on Allah's saying,

﴿إِنَّ زَلْزَلَةَ السَّاعَةِ شَىْءٌ عَظِيمٌ﴾

(Verily, the earthquake of the Hour (of Judgement) is a terrible thing.) "Before the Hour.'' Others said that this refers to the terror, fear, earthquakes and chaos that will happen on the Day of Resurrection, in the arena (of Judgement), after the resurrection from the graves. This was the view favored by Ibn Jarir, who took the following Hadiths as evidence: Imam Ahmad recorded that `Imran bin Husayn said that when the Messenger of Allah was on one of his journeys and some of his Companions had fallen behind, he raised his voice and recited these two Ayat:

﴿يأَيُّهَا النَّاسُ اتَّقُواْ رَبَّكُمْ إِنَّ زَلْزَلَةَ السَّاعَةِ شَىْءٌ عَظِيمٌ - يَوْمَ تَرَوْنَهَا تَذْهَلُ كُلُّ مُرْضِعَةٍ عَمَّآ أَرْضَعَتْ وَتَضَعُ كُلُّ ذَاتِ حَمْلٍ حَمْلَهَا وَتَرَى النَّاسَ سُكَـرَى وَمَا هُم بِسُكَـرَى وَلَـكِنَّ عَذَابَ اللَّهِ شَدِيدٌ ﴾

(O mankind! Have Taqwa of your Lord! Verily, the earthquake of the Hour is a terrible thing. The Day you shall see it, every nursing mother will forget her nursling, and every pregnant one will drop her load, and you shall see mankind as in a drunken state, yet they will not be drunken, but Allah's torment is severe.) When his Companions heard that, they hastened to catch up with him, because they knew that he wanted to say something. When they reached him, he said:

«أَتَدْرُونَ أَيُّ يَوْمٍ ذَاكَ، ذَاكَ يَوْمُ يُنَادَى آدَمُ عَلَيْهِ السَّلَامُ، فَيُنَادِيهِ رَبُّهُ عَزَّ وَجَلَّ، فَيَقُولُ: يَا آدَمُ ابْعَثْ بَعْثَكَ إِلَى النَّارِ، فَيَقُولُ: يَا رَبِّ وَمَا بَعْثُ النَّارِ؟ فَيَقُولُ: مِنْ كُلِّ أَلْفٍ تِسْعُمِائَةٍ وَتِسْعَةٌ وَتِسْعُونَ فِي النَّارِ، وَوَاحِدٌ فِي الْجَنَّة»

(Do you know what Day that is That is the Day when Adam will be called. His Lord will call him and will say: "O Adam, send forth (those of your progeny) who are to be sent to the Fire.'' He will say, "O Lord, how many are to be sent to the Fire'' He will say, "From every thousand, nine hundred and ninety-nine will be in the Fire and one will be in Paradise.'') His Companions were filled with despair and stopped smiling. When he saw that, he said:

«أَبْشِرُوا وَاعْمَلُوا، فَوَالَّذِي نَفْسُ مُحَمَّدٍ بِيَدِهِ إِنَّكُمْ لَمَعَ خَلِيقَتَيْنِ مَا كَانَتَا مَعَ شَيْءٍ قَطُّ إِلَّا كَثَّرَتَاهُ يَأْجُوجُ وَمَأْجُوجُ، وَمَنْ هَلَكَ مِنْ بَنِي آدَمَ وَبَنِي إِبْلِيس»

(Be of good cheer and strive hard, for by the One in Whose Hand is the soul of Muhammad, you will be counted with two creations who are of immense numbers, Ya'juj and Ma'juj, and those who have already died of the progeny of Adam and the progeny of Iblis.) Then they felt happier, and he said:

«اعْمَلُوا وَأَبْشِرُوا، فَوَالَّذِي نَفْسُ مُحَمَّدٍ بِيَدِهِ، مَا أَنْتُمْ فِي النَّاسِ إِلَّا كَالشَّامَةِ فِي جَنْبِ الْبَعِيرِ أَوِ الرَّقْمَةِ فِي ذِرَاعِ الدَّابَّة»

(Strive hard and be of good cheer, for by the One in Whose Hand is the soul of Muhammad, in comparison to mankind you are like a mole on the flank of a camel or a mark on the foreleg of a beast.) This was also recorded by At-Tirmidhi and by An-Nasa'i in the Book of Tafsir in their Sunans. At-Tirmidhi said, "It is Hasan Sahih.''