كتاب السهو
Read the English translation first, with the original Arabic directly underneath.
It was narrated that 'Aishah, may Allah (SWT) be pleased with her, said:
"I knocked at the door when the Messenger of Allah (ﷺ) was offering a voluntary prayer. The door was in the direction of the Qiblah so he took a few steps to his right or left and opened the door, then he went back to where he was praying."
أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ حَدَّثَنَا حَاتِمُ بْنُ وَرْدَانَ، قَالَ حَدَّثَنَا بُرْدُ بْنُ سِنَانَ أَبُو الْعَلاَءِ، عَنِ الزُّهْرِيِّ، عَنْ عُرْوَةَ، عَنْ عَائِشَةَ، - رضى الله عنها - قَالَتِ اسْتَفْتَحْتُ الْبَابَ وَرَسُولُ اللَّهِ صلى الله عليه وسلم يُصَلِّي تَطَوُّعًا وَالْبَابُ عَلَى الْقِبْلَةِ فَمَشَى عَنْ يَمِينِهِ أَوْ عَنْ يَسَارِهِ فَفَتَحَ الْبَابَ ثُمَّ رَجَعَ إِلَى مُصَلاَّهُ .