Sahih al-Bukhari 1209
Sahih al-Bukhari · Book 21: Actions while Praying · What kind of actions are permissible during As-Salat
Narrated Aisha:
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ ، حَدَّثَنَا مَالِكٌ ، عَنْ أَبِي النَّضْرِ ، عَنْ أَبِي سَلَمَةَ ، عَنْ عَائِشَةَ ـ رضى الله عنها ـ قَالَتْ كُنْتُ أَمُدُّ رِجْلِي فِي قِبْلَةِ النَّبِيِّ صلى الله عليه وسلم وَهُوَ يُصَلِّي، فَإِذَا سَجَدَ غَمَزَنِي فَرَفَعْتُهَا، فَإِذَا قَامَ مَدَدْتُهَا.
I used to stretch my legs towards the Qibla of the Prophet (ﷺ) while he was praying; whenever he prostrated he touched me, and I would withdraw my legs, and whenever he stood up, I would restretch my legs.