Yahya bin Abu Kathir reported,

I asked Abu Salama bin Abdul-Rahman, "Which part of the Quran was revealed first?"He replied, "You who are wrapped in a cloak" [Muddaththir 74:1].I said, "Or was it 'Recite' [Alaq 96:1]?"Abu Salama said, I asked Jabir bin Abdullah, "Which part of the Quran was revealed first?"He replied, "You who are wrapped in a cloak" [Muddaththir 74:1].I said, "Or was it 'Recite' [Alaq 96:1]?"Jabir said, "Let me tell you what the Messenger of Allah ﷺ told us. He said, 'I stayed in retreat at Hira for a month. When my time there was over I came down and made my way into the floor of the valley. Then I was called. I looked in front of me, behind me, to my right and to my left, but I saw no one. I was called again. I looked, and again saw no one. I was called a third time, and I raised my head, and there he was upon a throne in the air (meaning Jibreel). A violent trembling seized me, so I went to Khadijah and said, "Cover me up," and they covered me and poured water over me. Then Allah revealed, "You who are wrapped in a cloak, arise and warn, and magnify your Lord, and purify your garments" [Muddaththir 74:1–4].'"In the narration of Ali bin Mubarak from Yahya the wording is, "and there he was, seated upon a throne between the heaven and the earth."

عن يحيى بن أبي كثير يقول

سألت أبا سلمة بن عبد الرحمن: أي القرآن أنزل قبل؟ قال: {يأيها المدثر}. فقلت: أو {اقرأ}؟ فقال: سألت جابر بن عبد الله: أي القرآن أنزل قبل؟ قال: {يأيها المدثر} فقلت: أو {اقرأ}؟ قال جابر: أحدثكم ما حدثنا رسول الله ﷺ قال: جاورت بحراء شهرا، فلما قضيت جواري نزلت فاستبطنت بطن الوادي، فنوديت فنظرت أمامي وخلفي وعن يميني وعن شمالي فلم أر أحدا، ثم نوديت فنظرت فلم أر أحدا، ثم نوديت فرفعت رأسي فإذا هو على العرش في الهواء (يعني جبريل) فأخذتني رجفة شديدة، فأتيت خديجة فقلت: دثروني، فدتروني، فصبوا علي ماء فأنزل الله عز وجل: {يأيها المدثر قم فأنذر وربك فكبر وثيابك فطهر} [سورة المدثر: ١-٤] وفي رواية علي بن المبارك عن يحيى: فإذا هو جالس على عرش بين السماء والأرض