Language:
كتاب الصلاة
8  
Prayers (Salat)
(28)
Chapter: Superiority of (praying) facing the Qiblah with the toes toward it as well
(28)
باب فَضْلِ اسْتِقْبَالِ الْقِبْلَةِ
Sahih al-Bukhari 391

Narrated Anas bin Malik:

Allah's Messenger (ﷺ) said, "Whoever prays like us and faces our Qibla and eats our slaughtered animals is a Muslim and is under Allah's and His Apostle's protection. So do not betray Allah by betraying those who are in His protection."

حَدَّثَنَا عَمْرُو بْنُ عَبَّاسٍ، قَالَ حَدَّثَنَا ابْنُ الْمَهْدِيِّ، قَالَ حَدَّثَنَا مَنْصُورُ بْنُ سَعْدٍ، عَنْ مَيْمُونِ بْنِ سِيَاهٍ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ مَنْ صَلَّى صَلاَتَنَا، وَاسْتَقْبَلَ قِبْلَتَنَا، وَأَكَلَ ذَبِيحَتَنَا، فَذَلِكَ الْمُسْلِمُ الَّذِي لَهُ ذِمَّةُ اللَّهِ وَذِمَّةُ رَسُولِهِ، فَلاَ تُخْفِرُوا اللَّهَ فِي ذِمَّتِهِ ‏"‏‏.‏
Reference : Sahih al-Bukhari 391
In-book reference : Book 8, Hadith 43
USC-MSA web (English) reference : Vol. 1, Book 8, Hadith 386
  (deprecated numbering scheme)