[Machine] Gabriel used to descend upon the Prophet with the Sunnah (traditions and teachings of the Prophet) just as he descends upon him with the Quran.
«كَانَ جِبْرِيلُ يَنْزِلُ عَلَى النَّبِيِّ ﷺ بِالسُّنَّةِ كَمَا يَنْزِلُ عَلَيْهِ بِالْقُرْآنِ»