Sahih Muslim 424
Sahih Muslim · Book 4: The Book of Prayers · The Command To Perform The Prayer Properly, To Complete It, And To Have Khushu' In It
Abu Huraira reported:
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ ، عَنْ مَالِكِ بْنِ أَنَسٍ ، عَنْ أَبِي الزِّنَادِ ، عَنِ الأَعْرَجِ ، عَنْ أَبِي هُرَيْرَةَ ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " هَلْ تَرَوْنَ قِبْلَتِي هَا هُنَا فَوَاللَّهِ مَا يَخْفَى عَلَىَّ رُكُوعُكُمْ وَلاَ سُجُودُكُمْ إِنِّي لأَرَاكُمْ وَرَاءَ ظَهْرِي " .
The Messenger of Allah (ﷺ) said: Do you find me seeing towards the Qibla only? By Allah, your bowing and your prostrating are not hidden from my view. Verily I see them behind my back.