Sahih al-Bukhari, Hadith 403 ⓘ
Narrated `Abdullah bin `Umar: While the people were offering the Fajr prayer at Quba' (near Medina), someone came to them and said: "It has been revealed to Allah's Messenger tonight, and he has been ordered to pray facing the Ka`ba." So turn your faces to the Ka`ba. Those people were facing Sham (Jerusalem) so they turned their faces towards Ka`ba (at Mecca).
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، قَالَ أَخْبَرَنَا مَالِكُ بْنُ أَنَسٍ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، قَالَ بَيْنَا النَّاسُ بِقُبَاءٍ فِي صَلاَةِ الصُّبْحِ إِذْ جَاءَهُمْ آتٍ فَقَالَ إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَدْ أُنْزِلَ عَلَيْهِ اللَّيْلَةَ قُرْآنٌ، وَقَدْ أُمِرَ أَنْ يَسْتَقْبِلَ الْكَعْبَةَ فَاسْتَقْبِلُوهَا، وَكَانَتْ وُجُوهُهُمْ إِلَى الشَّأْمِ، فَاسْتَدَارُوا إِلَى الْكَعْبَةِ.
also referenced under: Book 8, Hadith 55 (In-Book) & Volume 1, Book 8, Hadith 397 (USC-MSA)