Chapter 28: The Book of Oaths
Nafi' reported: A mention of Allah' s Messenger (ﷺ) observing 'Umra from ja' rina was made before Ibn 'Umar. He said: He did not enter into the state of Ihram from that (place), and Umar had taken a vow of observing I' tikaf for a night during the days of Ignorance. The rest of the hadith is the same.
Sahih Muslim 1656e