Sahih al-Bukhari, Hadith 741 ⓘ
Narrated Abu Huraira: Allah's Messenger said, "You see me facing the Qibla; but, by Allah, nothing is hidden from me regarding your bowing and submissiveness and I see you from behind my back."
حَدَّثَنَا إِسْمَاعِيلُ، قَالَ حَدَّثَنِي مَالِكٌ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " هَلْ تَرَوْنَ قِبْلَتِي هَا هُنَا وَاللَّهِ مَا يَخْفَى عَلَىَّ رُكُوعُكُمْ وَلاَ خُشُوعُكُمْ، وَإِنِّي لأَرَاكُمْ وَرَاءَ ظَهْرِي " .
also referenced under: Book 10, Hadith 135 (In-Book) & Volume 1, Book 12, Hadith 708 (USC-MSA)