أَخْبَرَنَا قُتَيْبَةُ، عَنْ مَالِكٍ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، عَنِ ابْنِ عُمَرَ، قَالَ بَيْنَمَا النَّاسُ بِقُبَاءٍ فِي صَلاَةِ الصُّبْحِ جَاءَهُمْ آتٍ فَقَالَ إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَدْ أُنْزِلَ عَلَيْهِ اللَّيْلَةَ وَقَدْ أُمِرَ أَنْ يَسْتَقْبِلَ الْكَعْبَةَ فَاسْتَقْبِلُوهَا . وَكَانَتْ وُجُوهُهُمْ إِلَى الشَّامِ فَاسْتَدَارُوا إِلَى الْكَعْبَةِ .
It was narrated that Ibn 'Umar said: "While the people were in Quba', praying the Subh prayer, someone came to them and said that revelation had come to the Messenger of Allah (PBUH) the night before, and he has been commanded to face the Ka'bah. So they turned around, and they has been facing toward Ash-Sham, but now they turned to face toward the Ka'bah." Translation Not Available
Book Ref: Sunan An Nisai Book 5 Hadith 493
Web Ref: Sunan An Nisai Vol 1 Book 5 Hadith 494