1. According to the early commentators, this earthquake will be a prelude to Resurrection. This will probably take place when the earth will begin to rotate in the reverse order, and the sun will rise in the west. In a lengthy tradition reported by Ibn Jarir, Tabarani and Ibn Abi Hatim from Abu Hurairah, the Prophet (peace be upon him) has stated that when the first Trumpet will be blown, there will be a general confusion. At the second all people will die and at the third they will be brought back to life and presented before Allah. At the first blowing of the Trumpet, the earth will begin to rock like a boat which is beaten about by huge waves, or like a hanging lamp which is moved from side to side by a strong wind.
This condition has been depicted in the Quran at several other places. For instance (Surah Al-Waqiah, Ayat 6); (Surah Al-Haqqa, Ayats 13-14); (Surah Al-Muzzammil, Ayats 14,17-18); (Surah An-Naziat, Ayats 6-9) and (Surah Al-Zalzalah, Ayats 1-3).
According to other commentators, this earthquake will occur when the dead will be brought back to life and presented before their Lord. Though this is supported by some traditions, we prefer the first interpretation (in spite of the fact that the tradition reported by Abu Hurairah is weak) because that is supported by clear verses of the Quran.
2. This is to show the intensity and horror of the earthquake. At that time there will be so much confusion and terror that mothers will forsake their dear children at the very time they will be suckling them.
3. It should be noted that it is not meant to depict here the condition of the Resurrection but to impress upon the people the dreadful torment of the Hour in order to admonish them to mend their ways. This is supported by the subsequent passage.