حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَحْيَى، عَنْ سُفْيَانَ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، عَنِ ابْنِ عُمَرَ ـ رضى الله عنهما ـ بَيْنَا النَّاسُ يُصَلُّونَ الصُّبْحَ فِي مَسْجِدِ قُبَاءٍ إِذْ جَاءَ جَاءٍ فَقَالَ أَنْزَلَ اللَّهُ عَلَى النَّبِيِّ صلى الله عليه وسلم قُرْآنًا أَنْ يَسْتَقْبِلَ الْكَعْبَةَ فَاسْتَقْبِلُوهَا‏.‏ فَتَوَجَّهُوا إِلَى الْكَعْبَةِ‏.‏

Narrated Ibn `Umar: While some people were offering Fajr prayer in the Quba' mosque, some-one came and said, "Allah has revealed to the Prophet (PBUH) Qur'anic instructions that you should face the Ka`ba (while praying) so you too, should face it." Those people then turned towards the Ka`ba. Translation Not Available

Book Ref: Sahih Bukhari Book 65 Hadith 4488
Web Ref:  Sahih Bukhari Vol 6 Book 60 Hadith 15