حَدَّثَنَا إِسْحَاقُ أَخْبَرَنَا مَالِكٌ عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ عَنِ ابْنِ عُمَرَ قَالَ بَيْنَمَا النَّاسُ بِقُبَاءَ فِي صَلَاةِ الصُّبْحِ إِذْ أَتَاهُمْ آتٍ فَقَالَ إِنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أُنْزِلَ عَلَيْهِ قُرْآنٌ اللَّيْلَةَ وَقَدْ أُمِرَ أَنْ يَسْتَقْبِلَ الْكَعْبَةَ فَاسْتَقْبِلُوهَا وَكَانَتْ وُجُوهُهُمْ إِلَى الشَّامِ فَاسْتَدَارُوا إِلَى الْكَعْبَةِ
مسند امام احمد بن حنبل · Hadith 5934
It was narrated that Ibn 'Umar said: Whilst the people were praying Fajr in Quba'; someone came to them and said: Revelation came to the Messenger of Allah (PBUH) last night and he was commanded to face towards the Ka'bah, so face towards it. They were facing towards Syria, so they turned to face towards the Ka'bah.
Sanad
حَدَّثَنَا إِسْحَاقُ أَخْبَرَنَا مَالِكٌ عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ عَنِ ابْنِ عُمَرَ