Ibn 'Umar said: The Prophet (ﷺ) used to observe I'tikaf during the last ten days of Ramadan. Nafi' said: “Abd Allah (b. 'Umar) showed me the place in the mosque where Messenger of Allah (ﷺ) used to observe I'tikaf”
SahihSahihSahihBook 14 · Hadith 153