It wasnarrated from Ibn 'Umar that:
When the Prophet (ﷺ) observedI'tikaf, his bedding would be spread for him, or his bed would beplaced there for him, behind the Pillar or Repentance. (ES)
English reference (ES): Vol. 1, Book 7, Hadith 1774 (ES)
Arabic reference (ES): Book 7, Hadith 1846 (ES)