I learned from Abu Musa that "Recite in the name of your Lord who created" [Alaq 96:1] was the first surah revealed to Muhammad ﷺ.
أخذت من أبي موسى {أقرأ باسم ربك الذي خلق} وهي أول سورة أنزلت على محمد ﷺ.
Ibn Abu Shayba (30846) and Hakim (2/220) both narrated it from Qurra bin Khalid, from Abu Raja Attaradi, from Abu Musa, who related it. Its chain is sahih. Hakim said, "Sahih according to the standard of the two sheikhs." Then came the interval of revelation, which lasted three years, and this is indicated by the hadith of Jabir bin Abdullah Ansari that follows.