Mishkat al-Masabih, hadith 2005

وَعَن أبي هُرَيْرَة قَالَ: كَانَ يعرض على النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ الْقُرْآنَ كُلَّ عَامٍ مَرَّةً فَعَرَضَ عَلَيْهِ مَرَّتَيْنِ فِي الْعَامِ الَّذِي قُبِضَ وَكَانَ يَعْتَكِفُ كُلَّ عَامٍ عَشْرًا فَاعْتَكَفَ عِشْرِينَ فِي الْعَامِ الَّذِي قُبِضَ. رَوَاهُ البُخَارِيّ

Abu Huraira said that the Qur’an was gone over* to the Prophet once annually, but that this was done twice in the year in which he died. He used to engage in private devotions in the mosque during ten nights every year, but he did this during twenty nights in the year in which he died. *Mirqat remarks that some expositors say the passive is used here because the person who went over the Quran to the Prophet was well-known, viz. Gabriel. Bukhari transmitted it.