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. (ID)
English reference (ID): Vol. 1, Book 7, Hadith 1774 (ID)
Arabic reference (ID): Book 7, Hadith 1846 (ID)