Ibn ‘Abbās said, “The entirety of Sūrah al-An’ām was revealed in Makkah at night, accompanied by seventy thousand angels, raising their voices around it in glorification of Allah.” Reference: At-Tabarani 12/215. There are many other variations of this hadith from different companions, including Abdullah b. Masʿūd, Abdullah b. Umar, Asmā’, Ali, Ubayy, but most of their chains contain weaknesses.