Abu Huraira reported: The Prophet, peace and blessings be upon him, would review the Quran once every year in Ramadan, and he reviewed it twice in the year he passed away. The Prophet would retreat in the mosque for ten days every year, and he secluded himself for twenty days in the year he passed away.
Source: Ṣaḥīḥ al-Bukhārī 4998
Grade: Sahih (authentic) according to Al-Bukhari
عَنْ أَبِي هُرَيْرَةَ قَالَ كَانَ يَعْرِضُ عَلَى النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ الْقُرْآنَ كُلَّ عَامٍ مَرَّةً فَعَرَضَ عَلَيْهِ مَرَّتَيْنِ فِي الْعَامِ الَّذِي قُبِضَ فِيهِ وَكَانَ يَعْتَكِفُ كُلَّ عَامٍ عَشْرًا فَاعْتَكَفَ عِشْرِينَ فِي الْعَام الَّذِي قُبِضَ فِيهِ
4998 صحيح البخاري كتاب فضائل القرآن باب كان جبريل يعرض القرآن على النبي صلى الله عليه وسلم