Sahih al-Bukhari 4494
Sahih al-Bukhari · Book 65: Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh)) · "And from wheresoever you start forth (for prayers), turn your face in the direction of Al-Masjid-al-Harãm (at Makkah), and wheresoever you are, turn your face towards it [when you pray)]..." (V.2:150)
Narrated Ibn `Umar:
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ ، عَنْ مَالِكٍ ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ ، عَنِ ابْنِ عُمَرَ ، قَالَ بَيْنَمَا النَّاسُ فِي صَلاَةِ الصُّبْحِ بِقُبَاءٍ إِذْ جَاءَهُمْ آتٍ فَقَالَ إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَدْ أُنْزِلَ عَلَيْهِ اللَّيْلَةَ، وَقَدْ أُمِرَ أَنْ يَسْتَقْبِلَ الْكَعْبَةَ، فَاسْتَقْبِلُوهَا. وَكَانَتْ وُجُوهُهُمْ إِلَى الشَّأْمِ فَاسْتَدَارُوا إِلَى الْقِبْلَةِ.
While some people were offering Fajr prayer at Quba mosque, someone came to them and said, "Qur'anic literature" has been revealed to Allah's Messenger (ﷺ) tonight, and he has been ordered to face the Ka`ba (of Mecca) so you too, should turn your faces towards it. Their faces were then towards Sham (Jerusalem), so they turned towards the Qibla (i.e. Ka`ba of Mecca).