Riyad as-Salihin The Book of I'tikaf The Messenger of Allah (ﷺ) used to observe I`tikaf in the last ten days of Ramadan. . https://parallelquran.com/hadith/riyad-as-salihin-589/ Riyad as-Salihin The Book of I'tikaf The Prophet (ﷺ) used to engage himself in I’tikaf (seclusion for prayers) in the mosque during the last ten nights of Ramadan till he passed away; thereafter, his wives followed this practice after him.. https://parallelquran.com/hadith/riyad-as-salihin-590/ Riyad as-Salihin The Book of I'tikaf The Prophet (ﷺ) used to observe I’tikaf every year (during Ramadan) for ten days; in the year in which he passed away, he observed I’tikaf for twenty days.. https://parallelquran.com/hadith/riyad-as-salihin-591/