(24) باب الأَمْرِ بِتَحْسِينِ الصَّلاَةِ وَإِتْمَامِهَا وَالْخُشُوعِ فِيهَا
Abu Huraira reported:
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.
Reference: Sahih Muslim 424
In-book reference: Book 4, Hadith 120
USC-MSA web (English) reference(deprecated numbering scheme): Book 4, Hadith 854