When the Prophet ﷺ observed I’tikaf, his bedding would be spread for him, or his bed would be placed there for him, behind the Pillar of Repentance.
عَنِ النَّبِيِّ ﷺ أَنَّهُ كَانَ إِذَا اعْتَكَفَ طُرِحَ لَهُ فِرَاشُهُ أَوْ يُوضَعُ لَهُ سَرِيرُهُ وَرَاءَ أُصْطُوَانَةِ التَّوْبَةِ