WHEN THE PROPHET, praise and peace be upon him, WENT INTO SECLUSION FOR TWENTY DAYS H 1296 "The Messenger of Allah, praise and peace be upon him, went into seclusion for ten days during the month of Ramadan but in the year in which he died he went into seclusion for twenty days." R 1296 Bukhari with a chain up to Abu Hurairah who related this.
1270- وعن أَبي هريرة رضي الله عنه ، قَالَ : كَانَ النبيُّ صلى الله عليه وآله وسلم يَعْتَكِفُ في كُلِّ رَمَضَانَ عَشْرَةَ أيَّامٍ ، فَلَمَّا كَانَ العَامُ الَّذِي قُبِضَ فِيهِ اعْتَكَفَ عِشْرِينَ يَوْماً . رواه البخاري .