The Covered is the 74th chapter of the Qur'an, with 56 verses.
Chronology
Many well-known authors' chronologies, including that of Ibn Kathir, place Surat al-Muddaththir as the second surah revealed to the Islamic Nabi) Muhammad, citing the hadith:
Jabir ibn Abd Allah told, I heard the Messenger of Allah – and he was narrating about the pause in Revelation – so he said in his narration: "I was walking, when I heard a voice from the heavens. So I raised my head, and there was an angel, the one that had come to me at Hira, sitting upon a chair between the heavens and the earth. I fled from him out of fear, and I returned and said: "Wrap me up! Wrap me up!" So they covered me. Then Allah, Most High revealed: "O you who are wrapped up! Arise and warn." Up to His saying: "And keep away from the Rujz!" before the Salat was made obligatory.
Sahih al-Bukhari, Sahih Muslim, Jami` at-Tirmidhi, Musnad Ahmad Ibn Hanbal, etc. Although reports exist of revelation order other than second, the thematic elements of preparation for the Day of Judgment and warnings for the non-believers are consistent with other early Meccan suras. According to Sayyid Qutb's exegesis, the first verses of this surah as well as those of Surah 73 represent Muhammad’s earliest revelations and those which prepare him for the ordeal of revelation.
Structure
Surat al-Muddaththir is structured thematically and chronologically. Containing 56 total verses, this surah was most likely revealed on at least two occasions and compiled retroactively. Verses 1-30 and 32-56 are composed of short, poetic lines which maintain rhyme structure and the Arabic rhetorical device of parallel construction. This is consistent with the verses of the early Meccan period. Verse 31 is unique in its prose-like syntax and length; it is easily the longest verse of this surah and is a glaring break with the rhyme structure that precedes and follows it. This type of verse is most common in the later Medinan revelations.
Major themes
There are several distinct thematic sections of this surah. The first is an injunction for self-preparedness. If verse 1 refers to the Prophet Muhammed : You, wrapped in your cloak, then the second verse serves to alert the Prophet to a changing environment from which he is charged with saving mankind: Arise, and give warning. Verses 3-7 are injunctions, then, for the Prophet to maintain cleanliness, monotheism, humility, and patience in his own life. These are all preparations for the revelation of the rest of the message. The next thematic section of Surat al-Muddaththir is a warning for the unbelievers. Verses 8-30 describe the rejection of God's word and the excruciating consequences that result. For he that has not been grateful for the bounty of God's blessing and demands more, disregarding the signs and revelations of God, will be cast into the Saqar, which here refers to the scorching fire of Hell. This image of an unbeliever emphasizes the individuality of the responsibility of obeying God's message: the onus falls upon the individual man to save himself from Hell. Verse 30 refers to nineteen angels who guard the pit of hell; this curious detail is expounded upon in the following verse, which is believed to be a Medinan addition. Some scholars, such as Sayyid Qutb, have stated that verse 31 serves as an explanation of verse 30 that was added after early Muslims and unbelievers alike questioned the specificity of the nineteen angels: "We have appointed none other than angels to guard the fire, and We have made their number a test for the unbelievers. Thus those who have been granted revelations in the past may be convinced and the believers may grow more firm in their faith; and so those who have been granted revelations and the believers will entertain no doubt; but the sick at heart and the unbelievers will ask, "What could God mean by this image?" Thus God lets go astray whomever He wills, and guides whomever He wills. No one knows your Lord's forces except Him. This is all but a reminder for mankind." Thus verse 31 explains the mystery of the nineteen angels by portraying the number as a marker of faith. True believers will not question it, as it is the word of God, and those who God has "led astray" will be troubled by doubts. The next section of Surat al-Muddaththir uses the tangible, accessible physical world as proof that the devastation which awaits the unbelievers will be equally real. It then transitions back to the theme of individual responsibility. Verses 37-47 describe the trial of the soul in Saqar, and the decisions of the individuals who found themselves there. There will be no intercession for them; once they rejected God's word, their eternal souls were doomed. Finally, the surah returns to the realm of the living to give its final injunction. Verses 49-56 emphasize the vital need for mankind to fear and glorify God. Having given the believers an image of what happens to those who do not heed the message, the surah ends with a reminder that ultimately, God controls the destiny of all mankind and that nobody will remember what God does not let him. This ultimate authority of God is the final image of Surat al-Muddaththir.