While some people were offering Fajr prayer in the Quba' mosque, some-one came and said, "Allah has revealed to the Prophet ﷺ Qur'anic instructions that you should face the Kaʿba (while praying) so you too, should face it." Those people then turned towards the Kaʿba.
أَنْزَلَ اللَّهُ عَلَى النَّبِيِّ ﷺ قُرْآنًا أَنْ يَسْتَقْبِلَ الْكَعْبَةَ فَاسْتَقْبِلُوهَا فَتَوَجَّهُوا إِلَى الْكَعْبَةِ
While some people were offering morning prayer at Quba' a man came to them and said, "A Qur'anic Order has been revealed to Messenger of Allah ﷺ tonight that he should face the Kaʿba at Mecca (in prayer), so you too should turn your faces towards it." At that moment their faces were towards Sham (i.e. Jerusalem) (and on hearing that) they turned towards the Kaʿba (at Mecca).
إِنَّ رَسُولَ اللَّهِ ﷺ قَدْ أُنْزِلَ عَلَيْهِ اللَّيْلَةَ قُرْآنٌ وَأُمِرَ أَنْ يَسْتَقْبِلَ الْكَعْبَةَ أَلاَ فَاسْتَقْبِلُوهَا وَكَانَ وَجْهُ النَّاسِ إِلَى الشَّأْمِ فَاسْتَدَارُوا بِوُجُوهِهِمْ إِلَى الْكَعْبَةِ
[Machine] Indeed, the Messenger of Allah ﷺ has been sent down with the Quran tonight and he has been commanded to face the Kaaba, so face it and circle around it, directing yourselves towards the Kaaba.
إِنَّ رَسُولَ اللهِ ﷺ قَدْ أُنْزِلَ عَلَيْهِ اللَّيْلَةَ قُرْآنٌ وَأُمِرَ أَنْ تُسْتَقْبَلَ الْكَعْبَةُ فَاسْتَقْبَلُوهَا وَاسْتَدَارُوا فَتَوَجَّهُوا نَحْوَ الْكَعْبَةِ