Sunan an-Nasa'i 3822
سنن النسائي#3822SahihIt was narrated from Ibn 'Umar that 'Umar had vowed -during the Jahiliyyah- to spend a day in 'Itikaf. He asked the Messenger of Allah about that, and he commanded him to perform the 'Itikaf
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih Muslim
In-book reference: 35:62