Allah (swt) addresses the Prophet (saws) by (O you who covers himself) and in the previous Surah He (swt) addresses him by saying: (O you who wraps himself). The Prophet (saws) told us about the time of Revelation, he said:

“While I was walking, I heard voices from the sky. I looked up, and behold ! I saw the same Angel who came to me in the cave of Hira’ sitting on a chair between the sky and the earth. I was too much afraid of him (so I returned to my house) and said, ‘Fold me up in garments!’ They wrapped me up. Then Allah revealed: ‘O you wrapped…and desert the idols before the prayer became compulsory.’”[1]

The Arabic word (Al-Muddaththir) is the one who wraps in his clothes in his cloak when he sleeps. Being wrapped in the clock could be taken literally, that is he was wrapped in his cloak and blanket. However, the verse may have another meaning than just being wrapped with a clock, but with an abstract one, namely, the cloak of Prophethood and Mission. As if Allah (swt) is saying to the Prophet (saws): O, you who covers himself with the great knowledge, boble behaviour and complete mercy:

[1] Sahih al-Bukhari: Book of Tafseer of the Prophet (pbuh), Chapter of “And purify your garments!”, Hadith No. 4925.