Narrated Aisha:
The commencement of the Divine Inspiration to Allah's Messenger (ﷺ) was in the form of true dreams. The Angel came to him and said, "Read, in the Name of your Lord Who has created (all that exists), has created man a clot. Read! And your Lord is Most Generous" ..(96.1,2,3)
USC-MSA web (English) reference: Vol. 6, Book 60, Hadith 479
Arabic reference: Book 65, Hadith 4955