The resumption of revelation…
The break in Divine Revelation lasted six months. Its resumption is recounted by the Blessed Prophet upon him blessings and peace:
“As I was walking one day I heard a voice from the sky. I lifted my head, and there he was; the Angel that had come to me at Hira, seated on a throne suspended on the horizon. I was terrified. I returned home, urging:
‘Cover me…cover me!’
(As I lay covered, Jibril –upon him peace- returned; and through him) Allah glory unto Him, revealed:
يَا أَيُّهَا الْمُدَّثِّرُ
‘O you who is covered! Arise and warn, And your Lord do magnify, And your garments do purify, And uncleanness do shun!’ (al-Muddaththir, 1-5)
Revelation continued uninterrupted thereafter.” (Bukhari, Tafsir, 74/4, 5; Muslim, Iman, 255-258)
The Almighty declares:
وَلَقَدْ وَصَّلْنَا لَهُمُ الْقَوْلَ لَعَلَّهُمْ يَتَذَكَّرُونَ
“And certainly We have made the word to reach them so that they may be mindful.” (al-Qasas, 51)
The unbroken continuance of Revelation is likewise to be counted among the miracles of the Quran. The successive revelation to the Messenger of Allah -upon him blessings and peace- of verses of such magnificence, defying imitation even if an attempt was to be made by the entirety of humankind with another species of being also called upon to help, can only confirm beyond the shadow of a doubt the Divine source of the Quran, providing one of the clearest proofs of it being impervious to human intervention.
Readily admitted, moreover, is the fact that even a simple volume of poems takes great toil to compile. However, regardless of the degree of care shown, it is impossible to argue that any of these manmade works is free from error. Such concerns are inapplicable to Divine Revelation, forever surviving in its original form, abounding in numerous miracles. That alone suffices to manifest the splendor of the Holy Quran.
Upon the coming of Chapter Muddaththir, the Messenger of Allah –upon him blessings and peace- immediately got up from where he had been laying. Not knowing what had just happened, Khadijah –Allah be well-pleased with her- was surprised:
“Why did you not continue your rest?” she asked.
“Time for resting is over”, said the Messenger of Allah -upon him blessings and peace-, informing her of the Revelation that had come anew.
During the first few days of the arrival of Revelation, Jibril –upon him peace- taught the Blessed Prophet -upon him blessings and peace- how to make wudu and perform salat. The command to perform a deed of worship which he was fond of had put a smile on his face.
Jubilant, the Messenger of Allah -upon him blessings and peace- returned home. Telling Khadija –Allah be well-pleased with her- of the great blessing given by Allah, glory unto Him, he instructed her how to make wudu and offer salat.
Source: Osman Nuri Topbaş, The Prophet Muhammed Mustafa the Elect, Erkam Publications
 Ibn Ishaq, p. 117; Ibn Hisham, I, 262-263.